Pre skin prick testing: A curfew required on herbals too

Abstract

Background

Allergic diseases are hypersensitivity disorders induced by an allergen specific immunoglobulin E (IgE) mediated response; Skin PrickTest (SPT) remains the gold standard for the in vivo assessment of IgEs. Many drugs are known to have anti histaminic effects and as such need to be stopped prior to the testing. However, the role of alternative system of medicine and other herbal remedies remains controversial in this regard.

Objectives

To study the effect of alternative system of medicine and other herbal remedies on the results of SPT.

Methods

The patients having a strong history and clinical symptoms of allergic diseases like allergic rhinitis, bronchial asthma and chronic urticaria were subjected to skin prick testing.

Results

There were six patients whose SPT results were negative although history and clinical symptoms suggested otherwise. On probing the drug intake of the patients prior to the testing, it was observed that the patients had taken certain herbal medications which interfered with the allergy testing and gave false negatives.

Conclusion

It is for the first time that a study has reported the significant effect of alternative medicine and other herbal supplements in suppression of skin prick test results. Therefore it is extremely important to ask properly the history of intake of alternative medicine and other dietary herbal ingredients and then insist on its abstinence for 10 days before SPT. A protocol wherein the allergist recommends to stop the use of any regional herbs prior to allergy testing will be the right step in improving the results of allergy testing and preventing false positives.