Patch Testing Clinic
Patients are investigated by patch testing and prick testing following a detailed history and physical examination. A patch test requires at least three visits to the clinic over a period of one week. At the first visit multiple patches of testing substances are placed on the skin and maintained in contact for two days. After two days, an initial assessment for allergic reaction is made. No further patches are applied but the patient returns after seven days for final assessment. Allergic reactions to substances in contact with the skin can take up to seven days to appear.