Pitted keratolysis - a study of various clinical manifestations

Pitted keratolysis (PK) is a common bacterial infection of skin characterized by noninflammatory superficial pits. Very few studies have focused on variations in clinical manifestations of PK. We conducted this study so that diagnosis of this treatable condition is not missed when it presents in an uncommonly perceived way.

Assessment of PK patients for various sites and morphologies.

A total of 30 patients with PK were assessed for various sites and morphologies. Bacterial and fungal cultures along with histopathology were performed.

Of 30 patients, 24 were females. Hyperhidrosis and malodour were the most common symptoms. Interdigital interface skin of the toes was the first site affected in most patients. Plantar skin was affected in all patients with involvement of interface skin of the toes in 29 patients. Other sites affected were palms, finger web spaces, nonglabrous skin, paronychium, and nail. Other than classical pits, scaly crusted inflammatory lesions with post-inflammatory hyperpigmentation (PIH) were noted. Associated keratoderma was also reported in some patients.

The presence of hyperhidrosis, malodour, and plantar lesions is consistent with previous studies. Interface skin between toes as the first site affected, involvement of toe web spaces, and associated keratoderma have been reported rarely. However, female preponderance, involvement of finger web spaces, nonglabrous skin, paronychium, nail changes, the presence of inflammation with crusting, and PIH have never been reported previously.

PK can involve web spaces, nonglabrous skin, and paronychium, and can cause nail changes. The lesions can be inflammatory with crusting and PIH.