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CPD • Clinicopathological case

Clinical and Experimental Dermatology

An asymptomatic annular patch on the palm I. Tatarkova, P. Cetkovska, P. Brodska and K. Pizinger Department of Dermatology and Venereology, Medical Faculty and Teaching Hospital, Charles University, Pilsen, Czech Republic doi: 10.1111/ced.12224

Clinical findings A 69-year-old white man presented with a 30-year history of a solitary, asymptomatic lesion on his right palm. The lesion had gradually increased in size over the years, but did not cause the patient any discomfort. His medical history included recurrent otitis since childhood, nonspecific hepatitis at the age of 7 years, and treated prostatic hyperplasia. Five years previously, the patient had undergone systemic treatment with antimycotics for onychomycosis involving his toenails; this treatment had no effect on the palmar patch. On physical examination, a well-circumscribed, rounded, slightly depressed erythematous patch, 25 9 8 mm in size, was seen on the thenar eminence of the patient’s right palm. (Fig. 1). A biopsy lesion was taken from the margin of the lesion for further examination.

Figure 1 A round, slightly depressed erythematous patch on the

right palm. (a)

Histopathological findings On histopathologic examination of the biopsy specimen, a sharp difference in the thickness of the uninvolved and involved skin was noted. In the central part, the stratum corneum (SC) was thinner, and consisted of compact orthokeratosis above a zone of parakeratosis. There was mild hypogranulosis beneath the parakeratosis. The lesional part of the skin also showed dilated capillaries in the papillary dermis (Fig. 2a,b).

(b)

What is your diagnosis?

Correspondence: Dr Iva Tatarkova, Department of Dermatology and Venereology, Medical Faculty and Teaching Hospital, Charles University, Dr Edvarda Benese 13, 305 99, Pilsen, Czech Republic E-mail: [email protected] Conflict of interest: none declared. Accepted for publication 19 May 2013

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Clinical and Experimental Dermatology (2014) 39, pp240–241

Figure 2 (a) Biopsy specimen showing a sharp difference in

height between uninvolved and involved skin; (b) the stratum corneum in the central part of the lesion was thinner and orthokeratotic. Haematoxylin and eosin, original magnification (a) 9 100; (b) 9 200.

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D CP Clinicopathological case

Diagnosis

Circumscribed acral hypokeratosis (CAH).

Discussion CAH, also known as circumscribed palmar or plantar hypokeratosis, is a rare benign dermatosis, which was first reported in 2002 by Perez et al.1 in a series of 10 patients. Several hypotheses regarding the pathogenesis of this disorder have been proposed, including an acquired epidermal malformation, a repetitive minor trauma or a localized abnormal keratinization defect.2 One publication suggested a possible inducement by human papillomavirus (HPV), based on the detection of HPV-4 in the lesion.3 The disorder usually affects middle-aged to elderly women (female:male ratio 4 : 1), with a mean age of 61 years.4 CAH presents clinically as a long-standing, erythematous patch, with a flat base, sharp margins, and a slightly raised border.5 The lesion is usually solitary, and localized over the thenar or hypothenar eminence of the palms, rarely appearing on the soles.4 Dermoscopy reveals step-like desquamation and homogeneous erythema with regularly distributed whitish spots. Histologically, the lesions show a sharp decrease in the thickness of the SC, causing an abrupt ridge to form at the point of transition from normal to involved skin. A decreased granular layer or dilated blood vessels in the underlying dermis might form other features. The clinical differential diagnosis for CAH includes porokeratosis of Mibelli, Bowen disease and squamous cell carcinoma.4,5 For accurate diagnosis, a biopsy should be taken from the border of the lesion to compare the cornified layer of the involved skin to that of the normal adjacent skin.4 Various treatments for CAH have been proposed in the literature; however, none has been considered effective. We started our patient on treatment with

ª 2013 British Association of Dermatologists

topical retinoids and later topical corticosteroids, but with no effect on the lesion. According to recent publications treatments using topical steroids, retinoids and hydrocolloid dressings have all been disappointing. Further case reports suggest cryotherapy, photodynamic therapy, and topical application of fluorouracil or calcipotriol, but the results remain controversial. Interestingly, spontaneous resolution of CAH has also been described.2

Learning points

•

CAH is a long-lasting rare dermatosis, which should be considered in the differential diagnosis of palmar and plantar lesions. • Further case reports, clinical trials, and clarification of the role of HPV are essential to better understand the origin and therapeutic treatment of this disorder.

References 1 Perez A, R€ utten A, Gold R et al. Circumscribed palmar or plantar hypokeratosis. a distinctive epidermal malforamtion of the palms or soles. J Am Acad Dermatol 2002; 47: 21–7. 2 Resnik KS, DiLeonardo M. Cirsumscribed palmar hypokeratosis: new observations. Am J Dermatopathol 2006; 28: 112–16. 3 B€ oer A, Falk TM. Circumscribed palmar hypokeratosis induced by papilloma virus type 4. J Am Acad Dermatol 2006; 54: 908–9. 4 Tosi D, Sala F, Crosti C. Cisrcumscribed palmar or plantar hypokeratosis. Report of an Italian case. Indian J Dermatol 2011; 56: 211–13. 5 Berk DR, B€ oer A, Bauschard FD et al. Circumscribed acral hypokeratosis. J Am Acad Dermatol 2007; 57: 292–6.

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