The Correlations between Clinical Features, Dermoscopic and Histopathological Findings, and Treatment Outcomes of Patients with Pitted Keratolysis

BACKGROUND: Pitted keratolysis (PK) is a superficial bacterial infection diagnosed mainly by clinical manifestations. Current data on its dermoscopic and histopathological findings, and the correlation of those findings, are limited. OBJECTIVES: To evaluate the clinical manifestations, dermoscopic, and histopathological findings of PK and to determine the correlations. METHODS: Forty naval cadets with PK and five cadets with normal feet were enrolled this cohort study and provided informed consent. Dermoscopy was independently applied and evaluated by 2 dermatologists. Shave biopsies were performed on 37 patients with PK. RESULTS: Pits were the most common dermoscopic finding (88.1%). The dermoscope had more sensitivity for the detection of PK than the naked eye examinations. Apart from the pits and the presence of bacteria, the most common histopathological finding for PK was color alteration of keratin. The presence of bacteria correlated with interrupted dermatoglyphic lines and the color alteration of keratin. Moreover, the presence of bacteria at the base of pits was related to worse treatment outcomes. CONCLUSIONS: Dermoscopy is a useful tool for PK diagnosis. Color alteration of keratin is another histopathological finding for PK. The presence of bacteria is associated with worse treatment outcomes.