A 12-year-old girl presented with malodorous pits over both soles associated with hyperhidrosis for the past three months. On cutaneous examination, multiple yellowish-brown circular crateriform pits (2-5 mm) with punched out appearance were seen over the ventral aspect of the great toe, the ball, and heel of both feet; the pits coalesced into large, shallow macerated furrows with focal erosion (Fig. 1). A characteristic sparing of the non-pressure bearing areas was noted. Potassium hydroxide mount of skin scrapings showed no fungal elements. Based on the characteristic history and cutaneous findings, a diagnosis of pitted keratolysis was made. She was treated with topical clindamycin and advised to avoid occlusive footwear; the lesions resolved in 3 weeks.

Fig. 1 Pitted keratolysis characterized by multiple crateriform pits with punched out appearance over the pressure-bearing areas of both feet.

Pitted keratolysis is a bacterial infection of the plantar stratum corneum, predominating the weight-bearing areas of the soles, commonly caused by gram-positive Kytococcus sedentarius. Although a straight forward diagnosis clinically, differential diagnosis include plantar warts (absense of skin markings), tinea pedis (erythema, scaling with fungal elements on KOH mount), and punctate keratoderma (tiny hard rounded bumps). Topical antibiotics and adequate preventive measures are recommended.