皮膚科および皮膚科疾患ジャーナル

Pigmented Contact Dermatitis

Abstract

Urmi Khanna and Sujay Khandpur

Pigmented Contact dermatitis is a non-eczematous variant of contact dermatitis clinically characterised by reddish-brown to slate grey pigmentation in a reticulate pattern, usually without any active or preceding clinical dermatitis. A detailed history is essential to establish the temporal correlation of exposure to a possible sensitizer, which further helps in differentiating PCD from its close mimickers such as melasma, lichen planus pigmentosus erythema dychromicum perstans, etc. Clinical variants of PCD include Riehl’s melanosis, pigmented cosmetic contact dermatitis, pigmented contact cheilitis and purpuric dermatitis. Histopathology shows pigment incontinence. Patch testing should be performed to identify the causative allergen and besides a papule or vesicle, a brown pigment may develop at the patch test site. Patients should be counselled regarding complete avoidance of the causative allergen and also the resistance of this condition to various treatment modalities.