Clinical Challenge: Hyperkeratotic Lesions of the Palms and Soles

Punctate keratoderma is a subtype of palmoplantar keratosis also known as Buschke-Fischer-Brauer syndrome. The hyperkeratotic papules of punctate keratoderma usually present in early adulthood, with a prevalence of fewer than 2 cases per 100,000 individuals.1 The disorder may be acquired or...

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Punctate keratoderma is a subtype of palmoplantar keratosis also known as Buschke-Fischer-Brauer syndrome. The hyperkeratotic papules of punctate keratoderma usually present in early adulthood, with a prevalence of fewer than 2 cases per 100,000 individuals.¹ The disorder may be acquired or familial. The familial type is usually transmitted in an autosomal-dominant manner and has variable penetrance.²

Lesions are localized to the surfaces of the palms and soles and may be asymptomatic or associated with pruritus.¹ When lesions occur over pressure points on the foot, walking becomes painful. In some variants, lesions resembling psoriasis may occur on other parts of the body.³ Punctate keratoderma has been associated with gastrointestinal malignancy, Hodgkin lymphoma, and breast and renal carcinoma.^4,5

The epidermal thickening in punctate keratoderma is caused by mutations in the AAGAB gene.⁶ The AAGAB gene codes for p34, a protein implicated in membrane trafficking. This results in disrupted epidermal growth factor receptor (EGFR) signaling, leading to the development of the characteristic hyperkeratotic lesions. EGFR abnormalities characterize a number of malignancies and may explain the association with punctate keratoderma.

Treatment options include mechanical keratolysis and application of emollients. Case reports have documented improvement with the oral retinoids alitretinoin and etretinate.^7,8

Anthony Rainey, BS, is a medical student at the Commonwealth Medical College in Scranton, Pennsylvania.

Stephen Schleicher, MD, is an associate professor of medicine at the Commonwealth Medical College in Scranton, Pennsylvania, and an adjunct assistant professor of dermatology at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia. He practices dermatology in Hazleton, Pennsylvania.

References:

1. Kawakami T. Hereditary palmoplantar keratosis. In: Oiso N, ed. Current Genetics in Dermatology. http://www.intechopen.com/books/current-genetics-in-dermatology/hereditary-palmoplantar-keratosis. February 6, 2013. Accessed February 9, 2016.
2. Alikhan A, Burns T, Zargari O. Punctate porokeratotic keratoderma. Dermatology Online Journal. 2010;16(1). http://escholarship.org/uc/item/4nj1z8mr. Accessed February 9, 2016.
3. Itin PH, Lautenschlager S. Palmoplantar keratoderma and associated syndromes. Semin Dermatol. 1995;14(2):152-161.
4. Bennion SD, Patterson JW. Keratosis punctata palmaris et plantaris and adenocarcinoma of the colon. A possible familial association of punctate keratoderma and gastrointestinal malignancy. J Am Acad Dermatol. 1984;10(4):587-591.
5. Stevens HP, Kelsell DP, Leigh IM, Ostlere LS, MacDermot KD, Rustin MH. Punctate palmoplantar keratoderma and malignancy in a four‐generation family. Br J Dermatol. 1996;134(4):720-726.
6. Pohler E, Mamai O, Hirst J, et al. Haploinsufficiency for AAGAB causes clinically heterogeneous forms of punctate palmoplantar keratoderma. Nat Genet. 2012;44(11):1272-1276.
7. Raone B, Raboni R, Patrizi A. Alitretinoin: a new treatment option for hereditary punctate palmoplantar keratoderma (Brauer-Buschke-Fischer syndrome). J Am Acad Dermatol. 2014;71(2):e48-e49.
8. Nomura T, Yoneta A, Pohler E, et al. Punctate palmoplantar keratoderma type 1: a novel AAGAB mutation and efficacy of etretinate. Acta Derm Venereol. 2015;95(1):110-111.