Dermoscopy has been incorporated as a useful dermatologic diagnostic tool in recent years. Its original indication—the differential diagnosis of pigmented lesions—has been broadened to include other noncancerous skin diseases, such as diseases of the hair,1 psoriasis, scabies,2 and connective tissue diseases.3 We report a case in which dermoscopy was used to rule out a pigmented plantar lesion.

A 67-year-old woman was referred to our department for the diagnosis of a presumed pigmented lesion on the sole of her right foot. The primary care physician suspected melanoma. The patient did not relate it to any injury and explained that the lesion had appeared over the previous month. She denied any preexisting pigmented lesion at this site.

On inspection, there was a macule of uneven pale brown color, with a diameter of 3mm. The type of lesion was not readily diagnosed with the naked eye (Fig. 1).

Figure 1.

Clinical image of the lesion: pigmented macule on the sole of the foot.

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We examined the lesion with a digital dermatoscope (MoleMax III, Derma Medical Systems, Vienna, Austria) (Fig. 2). A coiled hair shaft was observed below a normal stratum corneum, simulating an accumulation of pigment. This finding led to a diagnosis of pilonidal sinus. Scraping of the stratum corneum with a #11 scalpel blade allowed the hair to be removed. We explained the harmless, benign nature of the plantar lesion to the patient. When asked about her habits, she denied working as a hair stylist. Hence, it was assumed that the hair had become embedded in the stratum corneum accidentally.

Figure 2.

Dermoscopy image: hairy shaft below the stratum corneum.

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Pilonidal sinus or “barber's sinus”4 is a well-known occupational skin disease that tends to affect hairdressers or barbers. These professionals can experience penetration of hairs under their skin. An inflammatory response and a foreign body granuloma often develop. The most common site for this disorder is the interdigital spaces of the hands, although cases on the soles of the feet have also been described.5 No inflammatory response was observed in our patient. Hence, the condition resembled coiling hairs that grow below the stratum corneum on the legs of some women after waxing or shaving. Confusion of pilonidal sinus with other processes is not uncommon, and there has even been a report of a case of a coiled hair below the stratum corneum of the pubic skin simulating a larva migrans.6

Dermoscopy was useful in this case and prevented unnecessary surgical removal of the lesion.