Identifying and treating contact dermatitis, hives, drug rashes and atopic flares — by Dr. Reena Sharma, MD Dermatology, including patch testing for chronic / unexplained allergies.
Skin allergies show up as contact dermatitis (rash where something touched skin), hives (urticaria, raised itchy welts), drug rashes, or flares of underlying conditions like eczema. Diagnosis is detective work — identifying the trigger is half the treatment. We do this systematically.
Common types we see
Contact dermatitis — rash from nickel jewellery, fragrance, hair dye, leather, latex, certain skincare ingredients
If you have unexplained chronic dermatitis or react to many products, we offer patch testing — 30 to 50 standardised allergens applied to your back for 48 hours. Reactions identify specific contact allergens so you can avoid them in future.
For acute reactions: oral antihistamines, topical anti-inflammatory, occasional short steroid course. For chronic: barrier care, identification of triggers, structured avoidance plan. Book a consultation for a structured allergy work-up.
Quick answers
Skin Allergy — Frequently Asked Questions
How is a skin allergy diagnosed?
History (timing, location, triggers), physical exam, sometimes patch testing for contact allergens. Blood tests for true allergies are rarely useful for skin reactions — patch testing is the gold standard for contact dermatitis.
What is patch testing?
Standardised allergens are applied to your back for 48 hours. The reaction patterns identify specific contact allergens (nickel, fragrance, preservatives, hair dye). Useful for chronic unexplained dermatitis.
My skin reacts to many products — what do I do?
You may have sensitive skin barrier rather than true allergies. We test for actual allergens vs. irritant reactions, then build a "safe" skincare routine using known-tolerated ingredients.
Are antihistamines enough?
For acute hives or mild itch, often yes. For chronic eczema or contact dermatitis, antihistamines manage symptoms but topical anti-inflammatories address the cause.
What about food-driven skin reactions?
In adults, true food allergy presenting as skin issues alone is rare. Most "food-driven" eczema/hives are coincidental. Allergy testing only if hives appear within minutes of specific foods.
When should I see a dermatologist urgently?
Widespread rash with fever, blistering rash, swelling of lips/tongue/face, breathing difficulty — go to ER first. For chronic itching, persistent rash over 4 weeks, or repeated suspected allergic reactions, book a consultation.
