Dermatology Online Journal

Focal Acral Hyperkeratosis
Steven Natow, M.D., M.B.A.
Dermatology Online Journal 7(1): 10

Department of Dermatology, New York University

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PATIENT: S.P., 29-year-old woman

DURATION: Since childhood

DISTRIBUTION: Hands and feet

History

The patient first noted lesions on her hands and feet in the fifth grade. She also noted that her palms were hyperhidrotic, but the lesions were otherwise asymptomatic. A skin biopsy specimen obtained about ten years ago showed non-specific benign features. She has developed new lesions and recently decided to have the lesions examined and treated, if possible. Tazarotene gel 0.05 percent was to be applied to the affected areas daily.

Family history was non-contributory.

Physical Examination

Multiple, 1-to-4-mm, skin-colored, yellow-orange papules, some coalescing into plaques, were present on the dorsal and palmar-dorsal borders of her hands and fingers and the edges of her feet.

Figure 1	Figure 2

Laboratory Data

None

Histopathology

The biopsy showed epidermal hyperkeratosis and hypergranulosis with a normal dermis. An elastic stain was normal.

Diagnosis

Focal acral hyperkeratosis

Comment

Focal acral hyperkeratosis, which was described in 1983, is considered to be a variant of acrokeratoelastoidosis of Costa.[1,2] Clinically, they are identical and differ only in histologic features; focal acral hyperkeratosis lacks the elastorrhexis seen in acrokeratoelastoidosis.

Focal acral hyperkeratosis is characterized by small, firm, yellow, waxy, and translucent papules which appear on the margins of the hands and feet during childhood.[3,4] The papules often coalesce to form plaques and may be present on the dorsal surfaces as well as the knees. The most characteristic site of these papules is the boundary between the dorsal and palmar or plantar skin, in the space between the thumb and forefinger, and scattered irregularly along the line of the palmodorsal junction on the thenar eminence. These lesions are usually asymptomatic but may be associated with hyperhidrosis. New lesions may appear slowly over the years.

The mode of inheritance is unknown, but most of the patients have been of African descent.[5] The differential diagnosis includes acrokeratoelastoidosis of Costa, degenerative collagenous plaques of the hands, keratoelastoidosis marginalis of the hands, verruca plana, acrokeratosis verruciformis of Hopf, colloid milium, xanthoma, and punctate palmoplantar keratoderma.

Although the condition is benign, it may cause embarrassment. Multiple therapies have been attempted for focal acral hyperkeratosis and acrokeratoelastoidosis, such as liquid nitrogen cryotherapy, salicylic acid, tretinoin, and prednisone; most have been unsuccessful. Etretinate 25 to 50 mg for six months, has been used with good results for focal acral hyperkeratosis, but recurrences were noted with discontinuation or reduction of the dose.[6] Owing to the reported efficacy of etretinate, we decided to use topical tazarotene gel.

References

1. Dowd PM, Harman RR, Black MM. Focal acral hyperkeratosis. Br J Dermatol 1983;109(1):97-103. PubMed

2. Costa OG, Horizonte B. Acrokeratoelastoidosis. Arch Dermatol 70:228, 1954

3. Korc A, Hansen RC, Lynch PJ. Acrokeratoelastoidosis of Costa in North America. A report of two cases. J Am Acad Dermatol 1985;12(5 Pt 1):832-6. PubMed

4. Blum SL, Cruz PD Jr, Siegel DM, Tigelaar RE. Hyperkeratotic papules on the hands and feet. Focal acral hyperkeratosis (FAH). Arch Dermatol 1987;123(9):1225, 1228. PubMed

5. Nelson-Adesokan P, Mallory SB, Leonardi CL, Lund R, Lombardi C$[corrected to Leonardi CL]. Acrokeratoelastoidosis of Costa [published erratum appears in Int J Dermatol 1996 May;35(5):380] Int J Dermatol 1995;34(6):431-3. PubMed

6. Handfield-Jones S, Kennedy CT. Acrokeratoelastoidosis treated with etretinate. J Am Acad Dermatol 1987;17(5 Pt 2):881-2. PubMed

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