Testing & Treatment

The current allergy management is to identify the causative allergen (Allergy producing particles, done by the diagnostic procedures mentioned below) and take preventive measures in subsequent exposures which will certainly prevent the occurrence of allergy reactions.
If the avoidance measures can’t be implemented, the sufferer may need to use preventive measures.If this is also not helpful, vaccine therapy is provided by administering the sensitive allergen to the body by different concentrations over a period of time, the body learns to accept the sensitized material as a part of the body similar to normal persons without reacting to the allergen exposure.Different routes of allergen desensitisation are currently done in the world. The Subcutaneous Injections (SCIT) were in vogue over a century and had limitations and were resisted, due to painful pricks, by the persons who suffer from allergies.To increase the adherence to therapy, new routes of administration emerged. In recent times in the West a popular, promising and user friendly route of administration is by sublingual swallow Immunotherapy (SLIT)*. The desensitisation induces allergen tolerance, reduces the allergic reaction and the immune system behaves normal as commonly seen in normal person without recurrence of symptoms.SLIT is popular among users over SCIT and successful with optimum results and it is at present a routine therapeutic tool.We offer the following diagnostic services:

 

  • In-Vivo tests – SPT, Prick – Prick test, Patch test, Serum test
  • In-Vitro allergy test – ImmunoCap and EIA
  • Pulmonary Function Test & DLCO
  • ECG
  • Nasal smear and Mucosal clearance test
  • Thermostimulatory test
  • Sputum analysis and culture sensitivity
  • Complete hemogram
  • Diet Provocation/Elimination
  • Drug Allergy

Common allergic conditions treated include:

  • Allergic Conjunctivitis – Eye allergies
  • Allergic Rhinitis – nasal allergies
  • Allergic Asthma, Bronchitis – Lung allergy
  • Urticaria, Eczema – Skin allergy
  • Atopic Dermatitis
  • Food allergy and additive intolerance
  • Drug and Latex allergy
  • Anaphylaxis and angio edema
  • Insect sting (Honey Bee) allergy
  • Cat Allergy
  • Chronic Cough
  • Contact Allergy
  • Environmental Allergies
  • Exercise-induced reactions
  • Frequent Colds
  • Hay Fever
  • Hypersensitivities
  • Hives
  • Immunologic Problems
  • Insect Allergies
  • Intolerances (food)
  • Itchy Eyes
  • Peanut & Nut Allergy
  • Pollen Allergy
  • Sinus Infection

Treatments

  • Phadia
  • Spirometry
  • This is the best test for immediate hypersensitivity (Type 1 allergy). It demonstrates tissue bound IgE and identifies the atopic state.
  • Prick test are the in vivo counterpart of the serum specific antibodies (RAST test) although the results do not always parallel each other.
  • Skin test can provide useful confirmatory evidence for a diagnosis made on clinical grounds. A positive skin prick test merely identifies sensitization to a particular allergen it does not predict clinical relevance independent of the history.

Skin Prick Test

A carefully performed and correctly interpreted prick test with a concentrated extract of high quality allergen is a simple, quick, cheap and safe method with a high degree of specificity and sensitivity. Therefore prick testing with a battery of routine allergens is still the first and basic procedure in diagnosing allergic diseases.

 

Blood Tests:

IgE

IgE levels are often elevated in cases of allergic disease but these levels cannot be considered pathogonomic signs of allergy. A normal IgE level does not exclude allergy, while definitely elevated levels may be seen in non-atopic people.

 

Specific IgE (RAST) and Immuno CAP RAST

The radioallergosorbent test (RAST) measures the amount of IgE that is directed to a specific allergen. RAST tests for particular allergens may be appropriate in those patients who present with a good history of sensitivity to a particular allergen, and yet produce consistently negative skin test results. Skin tests are generally considered to be more sensitive than RAST assay and it is rare though not unknown for a patient to be skin test negative and RAST positive. The usual explanation is that the extracts used for skin testing were defective.

For inhalant allergies, the sensitivity of the RAST system is 60-80% and the specificity is higher than that of the skin prick tests.

A recent study published in April 2001, Vol. 86, No.4 of AAA&I, ‘Precision of Commercial labs ability to classify positive and negative allergen- specific IgE results’, shows that not all commercial labs provide reproducible and accurate results.

The Pharmacia CAP RAST (a modified RAST system) was found to be the best.

 

Indications for RAST (over skin prick test)

  • Severe generalized eczema.
  • When a patient demonstrates demographism.
  • When a patient is on antihistamines, which for some reason cannot be temporarily discontinued.
  • Patients apprehensive about skin prick test.
  • Patients suspected to be acquisitively sensitive to certain foods

A recent study using Pharmacia CAP-RAST in children with atopic dermatitis demonstrated that quantification of food-specific IgE provided increased positive predictive accuracies for milk, egg, peanut, and fish sensitivity compared to skin prick tests. As shown below a patient with a serum food allergen-specific IgE level in excess of the 95% predictive value may be considered reactive, and an oral food challenge would not be considered necessary. These tests are also useful in predicting when follow-up challenges are likely to be negative (i.e. when patients “outgrow” their food allergy)

 

CAP-RAST 95% positive predictive values:

(Adapted from Sampsom, H A, J Allergy Clin Immun)

Food 95% PPV Sensitivity Specificity
(kUa/l) (%) (%)
Egg 6 72 90
Milk 32 51 98
Peanut 15 73 92
Fish 20 40 99

 
Choice of Allergens
The choice of allergens selected to some extent depends on the age of the patient. The allergic child under 2 should always have IgE to milk, egg, wheat, peanut and soy estimated. In this age group foods rather than inhalant pattern is seen. As the child reaches school age an inhalant pattern begins to appear. By the time the child is a teenager the pattern is usually one of a pure inhalant allergy.

 

Patch Testing
Patch testing is the diagnostic test of allergic contact dermatitis and differentiates it from irritant dermatitis. Allergic contact dermatitis is a cell mediated (Type 4) reaction that produces an eczematous reaction initially confined to the site of contact. The cell-mediated response appears 7 to 14 days after initial sensitization and reactivates within 2 to 5 days of re-exposure. Patch testing is used to identify the sensitising substance. Once identified, strict avoidance is necessary to avoid further skin reaction. The ‘memory’ for the reaction is usually carried by the skin for life.

 

Clinical Indications:

  • To differentiate allergic contact dermatitis from irritant dermatitis
  • Atopic dermatitis, especially in adults with chronic hand eczema, eyelid eczema or eczema confined to the lips and perioral regions, head and neck regions and feet.
  • Occupational contact dermatitis. The vast majority of occupational skin diseases are caused by contact dermatitis and 90% of this is due to irritation and not sensitisation. This can be important in medico-legal cases. Occupations that carry a high risk of skin irritations include hairdressing, domestic work, floral workers, nursing, mechanics, printers, bar tending and food processing.