Invisible dermatoses

′Invisible dermatoses′ is a concept which has not received wide recognition, but is nevertheless very important both clinically and histologically. The term invisible dermatoses has been used in two contexts: a) Diseases, with out definite clinical features, and are therefore "invisible" to the clinician, but yet can be diagnosed by special investigations. b) Dermatoses which present with definite and obvious clinical features, but subtle or hidden histological features and are therefore "invisible" histologically. Diagnosis of such diseases represents a great challenge to both the dermatologist and dermatopathologist. This article discusses such diseases and offers clues and tools for their diagnosis. Diagnosis of such ′Invisible dermatoses′ needs proper awareness, recognition of subtle features, special stains, special investigations such as immunofluorescence and histochemistry and proper clinicopathological correlation.