Skin Allergy Assessment and Patch Testing in Dubai
Skin allergy is two different things. Hives, or urticaria, are itchy raised weals that come and go within hours and are usually not caused by anything you touched. Allergic contact dermatitis is an eczema-like rash where a substance met the skin, and it is diagnosed by patch testing. At Smart Care Polyclinic in Deira, a specialist dermatologist works out which you have, treats what can be treated, and arranges patch testing where it will change the answer.
For: hives, rashes from products or jewellery, unexplained itch
Takes: a 20-30 minute consultation; patch testing by referral
Price: consultation AED 125
What it is
Hives are weals that appear, itch and vanish within a day, moving around the body. In most people they are not an allergy to food or anything external, however strongly it feels that way; they are the skin's mast cells releasing histamine, often triggered by infection, medicines, heat, pressure or nothing identifiable. Acute hives settle within six weeks; chronic hives can last months and are controlled with regular non-drowsy antihistamines, stepped up as needed. Blood tests are not usually helpful unless the history points somewhere.
Allergic contact dermatitis is a delayed reaction to something touching the skin — nickel in jewellery and buttons, fragrance, preservatives in cosmetics, hair dye, rubber, adhesives. The rash is eczema-like, appears one to three days after contact, and sits where the contact was: the earlobes, the eyelids from nail varnish, the hands.
Patch testing is the only way to identify the culprit. Small amounts of standard allergens are taped to the back for two days and read at two and four days, following the European Society of Contact Dermatitis guideline on how the test is done and interpreted.1 It is arranged by referral to a centre that runs it, with the dermatologist's assessment and a list of your products so the right series is tested. Blood allergy tests do not detect contact allergy, which is a common misunderstanding.
What the consultation does
Sorts the rash into its type, treats the inflammation, and works out whether a cause needs finding. For hives that means antihistamines and a search for triggers; for contact dermatitis it means a topical steroid to settle the skin, avoidance advice, and patch testing where the pattern suggests an allergen. A photograph of the rash at its worst, and the products you use, are the most useful things to bring.
Urgent signs
Swelling of the lips, tongue or throat, difficulty breathing, or hives with faintness is anaphylaxis and needs emergency care immediately, not a dermatology appointment. Hives on their own, however dramatic, are not dangerous.
The consultation, and what follows from it
Dermatology consultation
Assessment, examination and a plan with every cost stated before anything further is done.
AED 125
Book
Questions patients ask
For contact allergy, yes, by patch testing, which is arranged by referral after the dermatologist's assessment. For hives, testing is rarely useful because most hives are not caused by an external allergen; the history is the test.
Rarely. Blood tests detect immediate-type allergy to foods and airborne allergens; they do not detect contact allergy, and they are usually unhelpful in chronic hives. The dermatologist will say if one is indicated.
Chronic spontaneous urticaria, in which the skin's mast cells are over-reactive without an external trigger. It is controlled with regular antihistamines and usually settles over months to a few years.
This guide is general information about a condition, not a diagnosis. Skin conditions overlap, and what looks like one thing is often another; the dermatologist's examination is what decides your treatment.
References
- Johansen JD, Aalto-Korte K, Agner T, et al.. European Society of Contact Dermatitis guideline for diagnostic patch testing - recommendations on best practice. Contact Dermatitis. 2015;73(4):195-221. PMID 26179009. doi:10.1111/cod.12432The European guideline on how diagnostic patch testing for contact allergy is performed and read.
Sources are listed for the specific statements they support. They are published research and guidance, not a substitute for a consultation — what applies to you is decided by a doctor who has assessed you.