Progressive pigmented purpuric dermatosis in skin of color: a dermoscopic and histopathological correlation

Abstract
Background: Progressive pigmented purpuric dermatosis (PPPD) is a chronic cutaneous presents with petechiae, purpura on hyperpigmented yellowish-brown macules or patches. Diagnosis is straight forward, sometimes may be challenging for the diagnosis. Dermoscopy is a non-invasive tool. It gives characteristic patterns in PPPD. However, dermoscopic descriptions in skin of color are limited to case reports. Here, dermoscopic evaluation in skin of color is studied in detail. Methods: It was a cross sectional observation study. Ethical clearance and written consent was obtained. Patients of skin type 4 and 5, attending dermatology clinic with suspected lesions of PPPD were selected serially. Handheld dermoscope was used for examination. Site for dermoscopic examination was considered as target area. Skin biopsy was taken. Dermoscopic patterns were analysed and features were correlated with histopathological changes. Results: Totally 30 patients with 27 males and 3 females were enrolled. Schamberg’s disease was commonest type noted in 21patients. Eczematoid, lichen aureus, and lichenoid types were seen in 2 (6.7%) each. Hence, overall occurrence of Schamberg’s disease was statistically significant (p=0.028). Commonest dermoscopic findings were brown pigment network and yellowish-brown dots/globules. Least common features included linear vessels and bluish globules. Distorted pigment network noted in 29 (96.7%). Conclusions: Dermoscopy of PPPD shows characteristic patterns of which pigment network, red globules and yellowish-brown globules are the basic features. These features correlate well with histopathological changes. Yellowish-brown globules and background are prominently observed in skin of color. Larger studies are recommended to validate these differences.