Patch testing – a powerful dermatological tool

The concept of contact dermatitis, an inflammatory cutaneous reaction to external agents, has evolved through the ages. Concurrently, patch testing, a means of establishing cutaneous allergy to specific agents, has been developed, with constant updates to the allergens tested, based on a continuously developing knowledge base and emerging trends seen in the population. In this article, we review the history of patch testing, detailing how it is performed and which patients would benefit from such investigation.