Patch Test Mumbai: Diagnosing Contact Allergies to Nickel, Cosmetics, & Orthopaedic Implants

Chronic, itchy, red skin rashes that recur in specific areas are often diagnosed as contact dermatitis. This condition occurs when the skin reacts to contact with external substances—such as cosmetic ingredients, metal jewelry, or preservatives. Unlike typical hives or hay fever, contact dermatitis is a delayed-type hypersensitivity reaction (Type IV), meaning symptoms take 48 to 96 hours to develop, making the trigger hard to identify without a diagnostic patch test. If you suspect an immediate reaction to medications instead of a delayed skin allergy, see our guide on Drug Allergy Testing in Mumbai.

What is a Patch Test?

Patch testing is different from a skin prick test. It does not use needles. Instead, small chambers containing specific, diluted allergen substances are taped securely to the patient's upper back. The patches are left in contact with the skin for 48 hours. The test requires three scheduled clinical visits over a week to monitor the slow, cell-mediated immune response as it develops. For a detailed breakdown of the test, view our dedicated page on the Patch Test procedure.

“Patch testing is the only scientific method available to identify the exact chemicals causing contact dermatitis. It requires precise application and professional readings at both 48 and 96 hours.”— Dr. Sunita Chhapola Shukla

Key Sub-types of Contact Allergies Evaluated

At Mumbai Allergy Centre, we use patch testing to diagnose several categories of chronic contact allergies:

• Nickel & Metal Allergy: Highly common in Mumbai, presenting as rashes from jewelry, jeans buttons, or metal clasps.
• Ortho Implant Metal Sensitivity: Testing for hypersensitivity to metals (nickel, cobalt, chromium) prior to joint replacements, or when a patient experiences unexplained joint pain or loosening after surgery. Learn more about orthopaedic implant patch testing.
• Titanium Patch Test: A specialized metal test for patients receiving dental implants or orthopaedic plates/screws. Learn more about titanium patch testing.
• Cosmetic & Perfume Allergy: Evaluating reactions to facial creams, hair dyes (PPD), fragrances (fragrance mix), and preservatives (such as parabens or methylisothiazolinone). Learn more about cosmetics patch testing.

The 3-Visit Patch Testing Protocol

To ensure accuracy, the patch test protocol must be followed precisely:

• Visit 1 (Day 0 - Application): The test panels are prepared and taped to the patient's upper back. The patient must keep their back dry—no showering, swimming, or heavy sweating—during this phase.
• Visit 2 (Day 2 / 48 Hours - Removal): The panels are removed, the skin is marked, and the first reading is recorded to look for initial skin inflammation.
• Visit 3 (Day 4 / 96 Hours - Final Reading): The final reading is conducted. This visit is critical, as many contact allergies are slow to react and only show up as an itchy, red bump on Day 4.