What would be the most appropriate test to diagnose the below-given condition?
A 45-year-old farmer has itchy erythematous papular lesions on face, neck, ‘V‘ area of the chest, dorsum of hands and forearms for 3 years. The lesions are more severe in summer and improve by 75% in winter.
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1. Skin biopsy B. Estimation of IgE levels in blood C. Patch test D. Intradermal prick test
Patch test-the history is suggestive of photodermatitis. patch test is used for diagnosis of photodermatitis.
patch test (photopatch test) : here, 2 patches containing photosensitising material is applied on 2 different sites on the body. one of them is irradiated with uva rays. the other is kept as control. development of eczema is looked for upto 72 hours.
analysis of results:
no development of eczema patient does not have photodermatitis
development of eczema under the patch irradiated with uva photodermatitis
development of eczema under both patches contact dermatitis