According to the brucellosis history, another four cases showed bits of spleen tissue that were inoculated into tubes containing the nutrient agar and small round colonies that appeared after incubation at 37 degrees centigrade for sixty eight hours. Upon examination of the stained smears under very high power, numerous micrococci were again visualized.

Thus, in the second presentation, David Bruce described the presence of similar bacteria in another fatal case with various organisms measuring from 0.0008 to 0.001 mm in diameter, singly and in pairs that were scattered in the organs.

Brucellosis

According to the brucellosis history, later reports revealed the pathology of the disease in humans and it was compared to typhoid fever and malaria, and thus, the bacteria were classified as gram negative. After the initial diagnosis of the disease, M.Louis Hughes published a monogram that contained detailed information about the disease that was present in enlarged spleens of very rare fatally infected humans.

Although there was no pathological evidence of the disease, the main cause was identified as lack of proper sanitary conditions. When the natural brucellosis history was defined, it marked the end of centuries of effort that started from the first clinical presentation of the disease.

The citation of such descriptions is often considered sufficient evidence that the disease had existed for long periods of time before its identity was established by an isolation of the etiological agent. According to Hughes, a disease pattern that was compatible with brucellosis was described by Hippocrates.

However, according to the brucellosis history, during the eighteenth and nineteenth centuries several medical writers related cases of intermittent fever suggestive of brucellosis. A large number of descriptions of the disease include intermittent typhoid, typho malarial fever, remittent fever, Mediterranean gastric remittent fever.

The history of brucellosis revelers that brucellosis was also known as Mediterranean fever, rock or Gibraltar fever, Malta fever Neapolitan fever, Cyprus fever and undulant fever.

Most authorities agree that the first accurate description of brucellosis in the brucellosis history as a disease entity was given by Marston in the year 542 when he was an assistant Surgeon in the British Army Medical Department, who wrote during the year 1860 on the description of the Mediterranean gastric Remittent Fever.

There were many other accounts of the disease in the history of brucellosis that was caused due to the etiological agent known as Micrococcus Melitensis and there was also a presentation of the clinical discussion of the disease. Thus, the disease is known to exist for over a century now and it is found in cattle’s ass well as human beings. Various vaccinations have been developed in order to prevent the spread of the disease.

Symptoms

Brucellosis undulant fever is a contagious disease that is caused by bacteria of the genus brucella. The disease is referred to as Brucellosis and it is known to affect animals as well as human beings. When an individual is infected with brucellosis he may show sign of brucellosis undulant fever. Major symptoms include rising and falling fevers that show a wavy pattern and thus the name undulant fever. The individual may also show a sign of excessive sweating that is associated with malaise.

The patient may also complain of weakness and fatigue and there may be symptoms of anorexia. Sometimes, there are headaches and muscular pains, and backaches are also seen in patients suffering from brucellosis undulant fever. Brucellosis is transmitted through ingestion of the disease causing bacteria that is present in the various types of animal products that are consumed by humans. In some cases, the infection may also result due to contact with an infected animal. Brucellosis fever is very common in veterinary doctors and laboratory workers who may have come in contact with an infected animal.

Brucellosis fever and excessive sweating is the major sign for recognizing the disease. The disease causing bacteria may be transmitted when the individual ingests contaminated unpasteurized milk produced from infected animal. It is also transmitted through direct contact with animal carcass that may be containing the brucellosis bacteria. If the aborted fetus from an infected animal is not discarded, it can also be the cause of infection. Therefore, proper precaution must be taken when dealing with an infected animal.

Chronic brucellosis

According to a medical journal, a detailed survey of the symptoms of chronic brucellosis was conducted based on observations of veterinary surgeons working in different regions. The observations were mainly conducted based on the symptoms during observation of cattle that were infected with brucella.

The common symptoms observed in chronic brucellosis included excessive sweating and weakness. Most of the patients show symptoms of malaise and irritability and depression. In case of chronic brucellosis, there were signs of rheumatism and arthritis.

The veterinary doctors also reported the presence of backache which was very significant in the case of people infected with chronic brucellosis. It was also found that common symptoms related to the alimentary canal were very much prevalent in all patients that were infected with brucellosis.

Headache and insomnia were found in chronic presentation of the disease. Furthermore, it was found that there was a high level of serological brucella antibody titers found in asymptomatic persons that were infected with chronic brucellosis. In fact, it was found that a large number of surgeons show symptoms of the disease within a period of five years. Therefore, proper precautionary measures must be applied when dealing with infected cattle.

Brucellosis is known to be transmitted to human beings when it is ingested in the form of unpasteurized milk that may contain the bacteria. It can also be transferred when the veterinary surgeon or other workers come in contact with the body fluid or infected meat from the cattle showing symptoms of brucellosis.

The individual handling cattle must wear gloves and other gear that is used for protection in order to avoid direct contact with the carcass. After the procedure is completed, the gloves and all other gear must be burned in order to avoid spread of the disease.

Brucellosis epidemiology

According to the brucellosis epidemiology, brucellosis is commonly found in cattle and is major cause of concern in the United States of America. In most cases, the risk of transmission is always there as the disease causing agent can be transmitted from the infected fetus. This usually occurs when the infected fetus is exposed to susceptible host.

However, research shows that the brucellosis epidemiology occurs when the disease causing agent is ingested by the cattle. This can be transmitted to other cattle through the process of reproduction. In this case, the infected semen is responsible for spreading the disease In many cases, the infected animal may not show any symptoms of the disease. Thus, the brucellosis epidemiology continues to propagate through infected milk that is produced by the cattle.

This infected milk is a major cause of infection in calves as well as humans who ingest the infected milk. The main form of transmission occurs when the healthy animal comes in contact with infected tissue of the fetus, or when it comes in contact with fluids that are expelled from the body of the infected animal during the birth process.

It is also available in the uterine fluids or in the form of vaginal discharges from infected animals. In case the female cow is infected, the brucellosis epidemiology leads to the abortion of the first pregnancy. In some case, the brucellosis epidemiology is confined to the lymph nodes and the tissue is found in the udder of the female cow. Thus, the calves could also become infected by feeding on milk produced by the infected cow.

Brucellosis Transmission to Humans

Brucellosis transmission occurs when the disease causing bacteria spreads from animals to humans. Some of the most common mode of brucellosis transmission includes contact infection, food borne infection, and air borne infection. The disease causing brucella genus bacteria are present in the tissue and body fluids and transmission occurs when the individual comes in direct contact with the bacteria. In most cases, the brucellosis transmission is done by contact with infected tissues of the infected animal.

It could also occur when the individual comes in contact with the infected animal’s blood or urine. The brucellosis infection is very common in the case of veterinary doctors and their assistants who may be involved in direct contact with vaginal discharge, aborted fetus and placenta of the infected animal during the process of childbirth. The bacteria may penetrate through the mucosa or conjunctiva and invade other organs. This type of infection is very commonly found in individuals involved in slaughterhouses. If there is a food borne infection, then brucellosis transmission may occur due to ingestion of contaminated unpasteurized milk or other dairy products that are made from the raw milk.

It has been found that fresh vegetables may also be a major source of infection as they may collect bacteria from the manure that is used to fertilize the soil. Contaminated water may also be a major source of infection as it may contain the excreta of infected animals leading to brucellosis transmission to humans. Brucellosis disease transmission could also spread when the individual inhales infected dust or aerosols containing the disease causing agent leading to brucellosis in humans.

Diagnosis of Brucellosis in Humans

Brucellosis is a contagious disease that affects cattle, goats, dogs and pigs. The disease causing bacteria can also spread to the humans, especially those that come in close contact with infected animals. The bacteria of genus brucella lodge themselves in the tissues and body fluids and thus one must be very careful when handling tissue and milk produced by infected animals. The bacteria may transmit through mucous membranes and lodge themselves in the lymph nodes and spleen.

If the individuals ingest contaminated unpasteurized milk and milk products, it could lead to the spread of brucellosis to the animals. It has been found that the diagnosis of brucellosis is very rare in the United States of America. Brucellosis is very prevalent as almost 200 to 300 cases are being reported on an annual basis. Moreover, people who are in contact may contract the disease when they come in contact with animals or infected meat. The individuals may be slaughterhouse workers, farmers, and even the veterinary doctors are also at a high risk.

The diagnosis of brucellosis includes mild flu like symptoms like fever, abdominal pain and back pain. There may be excessive sweating associated with undulant fevers in the patient suffering from brucellosis. The diagnosis of brucellosis in some cases also showed symptoms of fatigue, headache, loss of appetite, weakness and weight loss. A major problem with the diagnosis of brucellosis is that most physicians are unable to identify the symptoms in the patients due to lack of information. This is important for the eradication of brucellosis in the cattle available in the herd.

Brucellosis in horses

Brucellosis in horses is caused by the disease causing brucella Abortus or Brucella Suis. It is also known as supportive bursitis that is most commonly recognized as fistulus withers or poll evil is the most common clinical presentation of the brucellosis in Horses.

In rare cases, abortion has been reported when there is brucellosis in horses. Also, it has been found that there are no known cases where brucellosis in horses has been transmitted to other horses, or other animals or even humans. The disease occurs when the bacteria is ingested by the horse while feeding in areas that lack proper sanitary conditions. The disease can be identified by testing the aborted fetus of the infected horses.

It is also known to reduce fertility in the horses. Therefore, proper precautionary measure must be taken when bringing the horse back from an animal fair or exhibition. The horse must be quarantined and tested for any infection before it is reintroduced in the herd. Thus proper preventive measures must be taken while buying horses and they must be tested for brucellosis in horses.

Brucellosis is also common in other significant animals like goats, pigs, sheep and other cattle found in the farm. Brucellosis is also found in human beings, especially those who are in contact with the infected livestock. This includes veterinary doctors, assistants, laboratory workers and others who are in contact with the infected horses. If any animal is identified with the disease, it is slaughtered in order to eradicate the disease causing agent.

Symptoms of Swine Brucellosis

Brucellosis is common in all forms of domesticated animals including cattle, sheep, pigs and goats. Swine Brucellosis is an infectious disease that is commonly found in pigs. The disease is caused by bacteria that are from the brucella suis strain and it has been spreading at a fast pace. The infection can be caused due to any form of contact with the secretions that are produced from the infected animal. In most cases, the symptoms of Swine brucellosis are caused by semen that may be infected and is transmitted during breeding.

The symptoms of Swine Brucellosis are caused due to the spread of the disease causing bacteria from the milk or other reproductive fluids that are formed from the infected pig. Placenta, aborted fetuses and urine from the infected pig can also cause the spread of the symptoms of swine brucellosis. Inhalation or eye contact with the pig that is infected can also lead to chronic illnesses. If the pig has a genetic tendency where it has a reduced response to the disease, it may also result in chronic brucellosis.

When symptoms of swine brucellosis occur in adult pigs, it leads to non specific infertility and in other cases, there is an increased incidence of abortions in the pigs and the animals also show a lack of sexual drive. Wild Boars may also show signs of the disease that is indicated by symptoms like arthritis, lameness, and posterior paralysis. In spite of all the advancements in the technology, research is still going on as there are no available vaccines for the disease. On the other hand, there is no cure for the symptoms of swine brucellosis.

Wild boars can cause serious infections in pigs and the most commonly found disease is known as swine brucellosis. The disease causing bacteria is very similar to that found in cows, horses, dogs or sheep. When brucellosis occurs in cattle, it is major cause of concern and proper precautions must be taken in order to curb the spread of the disease. Clinical presentation of the disease includes abortions in sows and the disease is identified when tests are conducted on the aborted fetus.

In the case of wild boars, swine brucellosis causes infertility. The bacteria can continue to exist in the pigs for a long period of time without showing any symptoms. But when swine brucellosis occurs in the cattle it can be very debilitating for the business as it causes a decrease in profits.

The swine brucellosis bacteria are transmitted through body fluids, especially those that are expelled from the uterus at the time of birth. These are also found in the semen of infected wild boars and in the infected sows. The most common method to eradicate the disease is by culling the infected animals. Proper care must be taken when handling infected wild boars.

One must wear gloves and disposable plastic when handling the carcass of the wild boars. One must make sure to properly dispose off all gloves and other gear used while handling the infected pigs. When bringing the pigs back from an affair, one must follow proper precautionary measures and isolate the animal in order to observe any signs of swine brucellosis in the pigs.

Watch video on Brucellosis below:

We have this informative article where we will be discussing what the Yeast infection in babies is. What is the cause and what are the symptoms and how it can be treated.

Let’s start with what the Yeast infection in babies is?

Yeast infection in babies is like the baby rash and it happens if the child’s vaginal area is not kept clean and dry. And the main cause is the fungus Candida.

What could be the causes of Yeast infection in babies?

There are many reasons due to which the Yeast infection in babies can happen.

• Firstly, if the mother has yeast infection during the delivery, high chances that the Yeast infection in babies happens.
• Yeast infection in babies can also happen if the mother fails to keep the vaginal area clean and dry for the kid.
• Unchanged diaper gives Candida (the fungus) best opportunity.
• Yeast infection in babies is also caused by inappropriate bathing of the child.
• Use of harsh soaps is very well known cause for Yeast infection in babies and adults.
• Another shocking cause can be Sexual abuse.
• If the mother has yeast infection, there is high chance she passes it on while Breast feeding.
• Also use of antibiotics for the child or the mother who is using antibiotic and feeds the kid.

The symptom of the Yeast infection in babies is any kind of white spots in the mouth or any rash that does not clear may be Yeast infection in babies.  Now any rash on the bottom does not mean that it is yeast infection however, if the rash does not disappear on any treatment or gets worse, this could be a symptom of Yeast infection in babies.

What Treatment can be used for Yeast infection in babies? Consulting a doctor, would be easy to identify the yeast infection. Just for tests he might take a scrapping of the skin and send it to lab and be assured this is not painful and won’t hurt the baby! Anti-Fungal medication can be used as prescribed.

Secondly, you have a home remedy to try too. There are many options available. You can use

• Tea tree oil (very diluted like 1drop of oil for 2 liters of water).
• Colloidal Silver.
• Cinnamon Oil.
• Yoghurt.
• Cider Vinegar
• Aloe gel
• Use of cool damp chamomile tea bag in the effected area.

So, here we have helpful information for all the mothers who want to make sure their babies are all happy and free from Yeast infection in babies. Make sure their diapers are changed regularly and it makes the best preventive measure. Take care, feel Special!!

Waardenburg syndrome comprises of many hereditary disorders, like the abnormal pigmentation of color, hearing loss and difference in the facial features.

Dr. Petrus Waardenburg reported a syndrome of dystopia canthorum. It is also called as Telecanthus.  In this situation the facial feature is a little abnormal, where the eyes are not spaced normally. There are far from each other than normal however, the pupils are placed normally. Due to dystopia canthorum one’s eyes appear too far (widely spaced) though they are not far.

People affected by dystopia canthorum often have white forelock and iris heterochromia. Which means that the hair growth on the forehead is white and the color of the eyes are different. And some may be partial in individual irises or may be the entire iris in one eye matching the pattern of iris. Mostly half the portion of the iris is brilliant blue.

In Dystopia canthorum due to the prominent nasal root and increased intercantal distance it may result to hypertelorism which means excessive width between two body organs.

Inheritance is typical for the Waardenburg syndrome. These are transmitted as autosomal dominant with interfamilial and intrafamilal variability. The major cause for this dystopia canthorum is mutation in multiple genes.

Any other malfunction related to dystopia canthorum may be due to involvement of micro deletions or contiguous gene defects.

The individuals affected with it may suffer from neural tube defects, cleft lip and palate. It also results in limb abnormalities and Hirsch sprung disease.

This syndrome is not known from any racial or ethnic predilection. Dystopia canthorum affects male and female with same frequency. It can be diagnosed in children at an early age however; in some individuals it may be undiagnosed until people learn about it.

Physical appearance of dystopia canthorum is complete or segmental heterochromia and Brilliant sapphire blue eyes.

There is a 50% chance in each pregnancy having an affected offspring of it. The features can be widely different within families and it is impossible to predict if the offspring would be less or more affected than the parents.

In some cases of dystopia canthorum surgery may be required to repair the severe cases. In some cases the neural tube defects, cleft lip or palate or the Hirsch sprung disease also needs a surgery.

It requires no special diet. It also does not restrict any activities. Currently for dystopia canthorum drug therapy is not a component of the standard of care.

Further impatient care may be needed for patients who are undergoing the surgery for repair of neural tube defects, cleft lip or palate, limb abnormalities, and Hirsch sprung disease.

This is important in order to find the right treatment in order to avoid various complications associated with this disease.

The patient has a hot potato sounding voice as he will be having a difficulty pronouncing vowels.

When an examination of the peritonsillar cellulitis abscess formation, the children will not be able to open their mouth and they will have difficulty swallowing food.

Webers glands are known to play an important role in the diagnosis of peritonsillar abscesses in the peritonsillar cellulitis.

The swelling of the lymph nodes and redness or edema of the area of tonsils particularly the affected part are some of the physical signs associated to it.

Peritonsillar cellulitis

Sometimes the uvula can get displaced or moved away towards the area which is not affected by the infection. This is sometimes associated with pain while swallowing.

Peritonsillar cellulitis can be caused due to the negligence in treating the complicated condition or by leaving it partially treated. This may cause the infection to spread across towards surrounding areas.

The causes can be both kinds of bacteria, that is aerobic as well as anaerobic. Streptocci, hemophilus as well as staphylococci may be responsible for these conditions.

The treatment for peritonsillar cellulitis is generally carried out in the most common way, that is surgical incision or draining of the infective pus from the area. This gives instant relief to the patient as it relieves pressure from the surrounding tissues.

Regular antibiotics tend to bring the condition to normalacy within the course period. This treatment can also be carried out when the patient is not concious or is under anesthesia.

However, this kind of treatment for peritonsillar cellulitis during anesthesia is avoided in case of children and elderly patients.

status epilepsy

In case of status epilepsy, various symptoms are associated with various disorders like multiple sclerosis, migraine and epilepsy.

According to the neurologists and medical professionals, paroxysmal disorders are often associated with sudden falls, headaches, and vertigo attacks.

In certain cases an individual suffering from paroxysmal disorders will be showing signs of memory loss, visual disturbances, seizures and anxiety.

The status epilepsy are of immense significance for medical clinicians, professional and their academic researchers who are working in various fields like neurology, psychiatry, epilepsy, epilepsy and internal medicine.

Electroencephalography is a technique that is applied for recording the electrical activity of the brain that is associated with paroxysmal disorders.

It has been found that when an individual is affected by status epilepsy, it does not affect consciousness.

Moreover since the incidence of the condition associated with partial status epilepticus is very rare, there is not much evidence that can be used for conducting research on this disease.

Thus the diagnosis is purely based on clinical findings. It involves various seizures that project from a discrete area of the cerebral cortex.

Moreover when EEG of the status epilepsy may not show an ictal activity and it may be normal.

In case the first line of treatment is not effective, then aggressive treatment will be required.

It has been found that around eighty five percent of patients who were affected by abscess benefitted by the needle aspiration method after the process of needle aspiration the affected area are marked for incision and drainage.

tonsillar abscess

This is found to be more effective than the needle aspiration method, but a quinsy tonsillectomy may be performed in the presence of tonsillar abscess.

But most patients prefer the needle aspiration methods as the first choice for treatment of PTA.

Some of the complications associated with peritonsillar abscesses or tonsillar abscess are known as parapharyngeal abscess.

The extension of abscess in other deep neck spaces leading to airway compromise.

It may be associated with septicemia and necrosis of surrounding deep tissues. In certain rare cases quinsies include mediastinitis.

Treatment of quinsies is through surgical incision and drainage of the pus.

When this procedure is performed it will considerably reduce the pain from the affected tissues.

In certain cases antibiotics may be used in order to treat quinces. It has been found that tonsillar abscess may occur in children as well as various adults.

The placentae are an organ that performs various important functions like supply of nutrition, elimination of toxins and exchange of gases with the developing fetus.

Abruption of placenta

Abruption of placenta are not just found in human beings but they are also characteristic of various reptiles like snakes and lizards.

There are other egg laying and marsupial mammals that consists of chorioviteline placentae form the connecting link between the developing fetus and the egg sac.

The placenta derive the nutrition from the egg sac and supply it to the developing fetus.

The placenta is connected to the developing fetus by various blood vessels that supply nutrients to the developing fetus.

The placenta also eliminates waste products from the uterus and facilitates the process of exchange of gases with the fetus.

Under normal conditions after the completion of the process of child birth the abruption of placenta detaches itself from the uterine wall and is expelled from the mother’s body.

This involves a certain amount of placental hemorrhage causing abruption of placenta.

But in certain cases where there is retained placenta after delivery and placenta accrete there is associated abruption of placenta that could lead to various complications in the mother’s body.

The placenta is an important organ found in the females and it performs various important functions as it supplies nutrients to the developing fetus inside the uterine wall.

It attaches the fetus to the uterine wall and eliminates wastes products effectively.

The placenta also aids in the process of exchange of gases between the developing fetus and the mothers body.

After the process of child birth the   gynecologist removes the fetus by cutting the umbilical cord and soon after this the placenta is expelled from the mother’s body.

But there are various anomalies like concealed hemorrhage, partial abruption and complete abruption.

In case of partial abruption these may be various complications. Abruption of placenta is also associated with excessive bleeding.

Note that the term Anaphylactic reactions denotes clinically similar reactions to certain agents e.g. radid-contrast dyes, which are not immunologically mediated.

Causes: Common precipitating agents for Anaphylactic reactions are shown on many sites online, though the cause remains unidentified in many cases.

Pathogenesis: Anaphylactic reactions are type I hypersensitivity reactions, mediated by specific IgE antibodies, formed in response to previous sensitization.

These antibodies are present on surface of basophils and mast cells and subsequent exposure to the same allergen leads to degranulation of mast cells and release of numerous chemical mediators.

Final effect of these mediators may manifest immediately with few minutes (acute phase reaction), or after many hours (late phase reaction), with three essential components of anaphylactic reactions — acute bronchospasm, increased vascular permeability and increased secretory activity of mucous glands.

Clinically, these reactions usually begin within 20-30 minutes of exposure to offending allergen, presenting with —

• Pen-oral tingling sensation, with flushing of face and extreme diaphoresis (earliest)

• Exudative manifestations e.g. urticaria, conjunctival congestion, sneezing, abdominal cramps with diarrhea,

• Stridor or bronchospasm with labored breathing,

• Sudden hypotension, bradycardia or shock, and

• A general feeling of sinking or impending doom, with rapidly developing unconsciousness.

Many cases die rapidly due to airway obstruction or cardiorespiratory arrest, unless treated immediately. Some patients after initial recovery develop recurrence (Biphasic reaction) after 1-8 hours due to late-phase reactions.

DID: Although history of exposure to an offending agent and catastrophic clinical picture is characteristic, anaphylactic reactions needs to be differentiated from

a) vasovagal attacks,

b) cardiac arrhythmia,

c) foreign body aspiration,

d) hypoglycemia and

e) acute poisoning.

Elevated IgE levels and eosinophilia differentiates anaphylaxis from anaphylactic reactions.

Management of anaphylactic reactions: Anaphylaxis is a life-threatening emergency, which needs immediate resuscitative measures and subsequent hospitalization for at least 24 hours to watch for late-phase reactions. Immediate resuscitative measures include —

a) Subcutaneous Adrenaline 1:1000 aqueous preparation (0.1 ml/kg; max 0.5 ml), followed by repeat doses at 15 minutes interval or continuous IV infusion (0.1 mg/kg/mm). In superficial venom injections e.g. insect stings, half of the SC dose (diluted in 2 ml saline) may be given locally, at the site of injection.

b) Respiratory support with airway maintenance, suction, oxygen/ventilatory support and tracheostomy, if needed.

c) Cardiovascular support with IV fluids and inotropes e.g. dopamine.

d) Nebulized salbutamol or IV theophylline, to control bronchospasm.

e) Antihistaminics e.g. Diphenhydramine (1 mg/kg 8- hourly) or Chlorphenarmine (0.3-0.5 mg/kg 8-hourly) for next 24-48 hours, to prevent late-reactions.

1) Systemic steroids e.g. IV hydrocortisone (5 mg/kg 6- hourly), although controversial in acute management, may help to decrease the duration and severity of manifestations.

g) If a precipitating agent e.g. drug is identified, a clear warning should be noted on medical records to prevent further episodes of anaphylactic reactions.

Allergen that causes allergic disorders denotes a substance capable of inducing IgE mediated reactions on exposure. The term allergen and antigen are not synonymous, as all allergens are not good antigens (e.g. Rag-weed pollens) and conversely all antigens are not necessarily allergens (e.g. vaccines).

Atopy denotes an inherited or familial predisposition for allergic disorders.

General Pathophysiology: Allergic disorders are triggered by the binding of an allergen to specific or reaginic IgE antibodies, attached on the surface receptors of circulatory basophils and tissue mast cells.

These reaginic antibodies are formed after an earlier exposure to same allergen i.e. sensitization. On subsequent exposure, antigen-IgE binding on the surface of basophils/mast cells provokes two different types of reactions —

a) Early-phase reactions within 20 minutes, due to degraulation of mast cells and release of pre-formed chemical mediators e.g. histamine and eosinophilchemotactic factors (ECF), presenting as urticaria, pruritis, sneezing, wheezing and hypotension e.g. anaphylaxis, asthma, allergic rhinitis or insect allergic disorders.

b) Late-phase reactions after 4-12 hours, due to influx of other allergic (basophils, eosinophils, mast cells) and inflammatory cells (polymorphs, lymphocytes) at the site of allergen exposure and consequent release of other chemical mediators e.g. leukotrienes and prostaglandins.

These mediators amplify and prolong allergic disorders inflammation as well as facilitate further differentiation of allergic cells and IgEproducing B-cells. Late-reactions have been implicated in development of long-term nasobronchial hyper-reactivity in allergic individuals.

General Principles in Diagnosis: Clinical spectrum of allergic disorders is extremely wide, ranging from life- threatening anaphylaxis to system-specific disorders like asthma, allergic rhinitis, atopic dermatitis or urticaria.

Allergic disorders are usually characterized by following common features —

a) Chronic course with intermittent exacerbations.

b) Cause-effect relationship with allergen.

c) Family history of atopic disorders.

d) In vitro laboratory abnormalities e.g.

— Peripheral eosinophilia (ABC >600 cell/mm3)

— Presence of eosinophils in body secretions

— Elevated 1gB levels (N: 10-20 IU/ml)

— Presence of antigen-specific 1gB

e) In vivo positive challenge tests e.g.

— Allergen skin testing* or

— Provocation tests**.

Allergen skin test is an important diagnostic tool to idcntify the causative allergen in many allergic disorders e.g. asthma or allergic rhinitis. These tests involve intradermal injections of mioiscule quantities of a battery of commercial available allergens (e.g. mites, dusts, pollens, danders and fungi), along with a negative (saline) and a positive (histamine) control, over forearm or back.

Local response to each allergen injection for allergic disorders i.e. erythema and wheel size is noted and compared with controls, after 10 minutes (early response) and 2-3 hours (late response). Severity of response indicates strength of cause-effect relationship, though false-positive/-negative results are common and results must be correlated with clinical observations.

**provocation or re-challenge tests involve deliberate exposure of the affected mucus membrane to suspected allergen, which may induce the allergen-specific clinical reaction. Commonly used provocation tests in allergic disorders include bronchial provocation test in asthma (nebulization of suspected allergen> spirometric changes) and oral provocation tests in food allergy or atopic dermatitis (ingestion of suspected food item> diarrhea or reappearance of skin lesions). Although useful in cases with equivocal in vitro laboratory results or skin testing, these tests are rarely used due to the risk of life-threatening reactions.

General Principles of Management in allergic disorders include — a) avoidance of suspected allergens, if possible; b) immunotherapy (desensitization) against un-avoidable allergens; c) specific pharmacotherapy to block the release or action of chemical mediators.

While specific therapeutic measures in management of individual allergic disorders have been discussed, some general principles are as follows —

a) Avoidance of allergens: Common allergens causing allergic disorders may be divided into 3 categories —

a) Inhalant allergens e.g. pollens, dust, dust-mite, danders and fungi,

b) Ingestant allergens e.g. food, and

c) Contactant allergens e.g. synthetic fabrics or elastics.

In addition, viral infections and smoke exposure, though not allergenic by themselves, are common triggering events for precipitation of acute attacks in children.

As the dictum goes, anything above the earth and below the sky may be allergenic. Further, atopic children are often allergic to many allergens at the same time. Considering this biological diversity, it is often difficult to identify and avoid specific allergens; though following precautions may be helpful —

• Avoidance of outdoor allergens e.g. dust exposure, visit to flowery gardens etc.

• Avoidance of indoor allergens with wet mopping of floor (dust); removal of indoor plants and regular cleaning of AC filters (fungi), soft toys (mites), pets (danders); pest control (cockroaches) etc.

• Avoidance of suspected dietary substances is often over emphasized, without much scientific basis. However, a proven cause-effect observation with particular foodstuff may be indication to avoid canned foods with preservatives, coloring agents etc.

• Avoidance of other allergic disorders triggering factors e.g. smoke exposure, viral infections etc.

According to immunopathogenesis, hypersensitivity disorder reactions may be divided into four types —

1) Type I (IgE mediated) reactions, also termed as allergy, are triggered by the binding of an allergen to specific or reaginic IgE antibodies attached on the surface receptors of circulatory basophils and tissue mast cells.

2) Type II (Cytotoxic) reactions are characterized by abnormal binding of 1gM or IgG antibodies to self- antigens, modified by external insult (e.g. drugs or infections), with complement activation and consequent target-tissue injury.

These hypersensitivity disorder reactions are usually tissue-specific e.g. autoimmune hemolytic anemia or thrombocytopenia (target antigen- cell membrane), myasthenia gravis (target antigenacetylcholine receptor) or Grave’s disease (target antigen-TSH receptors).

3) Type III (Immune-complex) reactions involve formation of soluble antigen-antibody complexes, which are either removed to reticuloendothelial organs or deposited at target tissues e.g. glomerular basement membrane, skin and synovium.

Immune-complex mediated complement activation leads to attraction of polymorphs at these sites with local inflammatory reactions and tissue damage i.e. Arthus reaction; or more systemic and widespread reactions i.e. Serum sickness.

Other common examples of these hypersensitivity disorder reactions are proteinuria in nephrotic syndrome and vasculitis syndromes e.g. Henoch-Schonlein purpura.

Serum sickness presents as fever, arthralgia, urticaria, lymphadenopathy and proteinuria, usually after 7-14 days of the administration of animal-derived antisera e.g. equine anti-snake venom, anti-tetanus serum etc. or certain drugs e.g. penicillin, cephalosporins etc.

4) Type IV (Delayed hypersensitivity disorder) reactions are mediated by antigen specific T-cells and macrophages due to recognition of antigen-peptide on antigen- processing cells by T-memory cells and release of inflammatory cytokines.

These hypersensitivity disorder reactions peak after 24- 48 hours of antigen exposure and include Tuberculin reactions, contact dermatitis, transplant rejection and Graft versus host disease, etc.