Granular parakeratosis


José M. Martín, MD Servicio de Dermatología Hospital Clínico Universitario Avda. Blasco Ibáñez 17 46010 Valencia Spain


A healthy 62-year-old woman was referred to our dermatology department with a 1-month history of a pruritic axillary eruption.

 On examination, multiple erythematous and brownish hyperkeratotic papules were seen in both axillae. Some of these lesions coalesced into plaques, with small areas of sparing, and a background erythematous color was also found in the axillary vaults (Fig. 1).

Figure 1.

Figure 1.

Multiple erythematous and brownish hyperkeratotic papules in the axillary vaults

 There was no involvement of other intertriginous sites and there were no associated systemic symptoms. The patient was not obese.

 The patient had removed the hair from her axillae with wax 3 weeks before the development of the eruption. Moreover, she had changed her antiperspirant 1 week before the onset of the lesions.

 A cutaneous biopsy for histologic analysis was performed. Histologically, the stratum corneum was thickened, with persistent nuclei together with countless small basophilic granules. The granular layer was preserved and, in some areas, hypergranulosis was found (Fig. 2). These findings were characteristic of granular parakeratosis.

Figure 2.

Figure 2.

Countless small basophilic granules in a thickened stratum corneum (hematoxylin and eosin; original magnification, ×400)

 The cutaneous lesions resolved completely after 1 week of treatment with topical betamethasone dipropionate and gentamicin sulfate (twice daily). The patient was urged to discontinue her use of deodorants.