Dermoscopy in the Diagnostics of Incontinentia Pigmenti Skin Lesions.

Introduction: Incontinentia pigmenti (IP) is a rare X-linked geno-dermatosis characterized by numerous findings. Skin biopsy and histopathological analysis are considered as minor criteria for the diagnosis of IP. We assume that dermoscopy can assist the earlier diagnosis of IP. Objectives: To gain experience in earlier diagnosis of IP by observing dermoscopic findings of cutaneous changes. Methods: We revised confirmed cases of IP and examined them using dermoscopy, comparing histopathological and dermoscopic results. Results: Stage I presented solitary and grouped vesicles in linear arrangement on erythematous skin. Early stage II presented star-shaped verrucous lesions on erythematous or pigmented skin. In well-developed lesions, dotted vessels surround keratotic part, some with thrombosed capillaries, resembling a viral wart. Stage III presented linear brown dots on the pigmented areas. Dermoscopic image was uniform in all the examined pigmented Blaschko linear changes. Stage IV presented numerous dotted vessels on the hypopigmented skin. Terminal hair was scarce or absent in all four stages. The surrounding normal skin had perifollicular depigmentations in stages III and IV. Conclusions: Dermoscopy of all four stages is very specific compared to the dermoscopy of inflammatory dermatoses and pigmentations. Stage III has very close clinical, histological and dermoscopic mimickers and needs to be carefully examined with obligatory genetic testing. Dermoscopy of the stage IV closely corresponds to histopathological findings and may be crucial as a quick tool in revealing potential IP gene carriers. Dermoscopy should be used in addition to clinical examination since the two methods are complementary.