Sir, Stucco keratosis is a benign keratotic papule occurring on the distal parts of the legs in elderly individuals. Histopathological analysis reveals characteristic church‐spire epidermal hyperplasia with orthohyperkeratosis. Common treatments for stucco keratosis include liquid nitrogen, electrodesiccation and curettage. However, these therapies seem unsatisfactory to patients presenting with numerous lesions. We report a case of stucco keratosis successfully treated using topical vitamin D3 (maxacalcitol).
A 68‐year‐old Japanese woman presented with an approximately 25‐year history of eruptions symmetrically distributed on the dorsa of the feet, and around the ankles and Achilles tendons. On examination, the lesions were round or irregular in shape, 2–4 mm in diameter, rough, whitish‐grey keratotic papules (Fig. 1a). These papules appeared to be ‘stuck’ on the skin, and more than 100 papules were noted. Skin biopsy from the dorsum of the foot showed a regular spiky papillomatosis covered with a basket weave‐like orthohyperkeratosis (Fig. 2). A small number of lymphocytes was seen in the upper dermis; however, there were no histological features characteristic of psoriasis including parakeratosis, diminished granular layer, elongation of rete ridges or vascular dilatation of dermal papillae. Also, no psoriatic plaques were observed at any site. Stucco keratosis was diagnosed and treatment with topical maxacalcitol was started. After 1 month of treatment, the lesions had almost cleared (Fig. 1b).
(a) Numerous small, keratotic papules on the dorsum of the foot. (b) The lesions cleared after 1 month of treatment.
Church‐spire epidermal hyperplasia with hyperkeratosis (haematoxylin and eosin; original magnification ×40).
Stucco keratosis was first described by Kocsard and Ofner in 1966,1 who noted a high incidence in elderly Australians with 77% in men and 33% in women. In the U.S.A.2 and Europe3 this condition is often seen in elderly men. Conversely, to our knowledge only 13 cases of stucco keratosis appear to have been reported in Japan. Although patients with stucco keratosis limited to a small number of lesions may not visit hospital, Aso et al.4 reported that they could not find any patients with this condition among 160 elderly individuals in a geriatric hospital in Japan. Differences in incidence may thus exist between ethnic groups or geographical regions.
Various treatment modalities have been attempted for stucco keratosis, including topical urea and salicylic acid. Etretinate therapy does not seem to be required for this benign asymptomatic condition. Although stucco keratosis can be removed by cryotherapy or curettage, these therapies are unsatisfactory to patients with numerous lesions such as in our case. Vitamin D3 analogues have recently gained attention as topical therapy for numerous skin diseases other than psoriasis, as vitamin D3 analogues can inhibit keratinocyte hyperproliferation and regulate epidermal differentiation.5 Maxacalcitol is a 1α,25‐dihydroxy‐22‐oxacalcitriol which has lower calcaemic effects and is more effective at inhibiting human keratinocyte proliferation and promoting differentiation than calcitriol.6 In the present case, therapy with maxacalcitol was very effective for stucco keratosis. Topical vitamin D3 may thus represent a suitable first‐choice therapy for stucco keratosis.
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Author notes
Conflicts of interest: none declared.
