Background
Acrokeratoelastoidosis (AKE) is a rare genodermatosis characterized by small, firm papules or plaques on the sides of the hands and feet. These nodules may result from an abnormality in the secretion or excretion of elastic material by fibroblasts in the dermis. Acrokeratoelastoidosis was first described in 1953 by Costa.[1]
Both autosomal dominant and sporadic forms have been observed. Acrokeratoelastoidosis is not congenital; it slowly arises at puberty, or sometimes later, and then remains stable. Usually, no treatment is necessary. Acrokeratoelastoidosis is similar to 2 other diseases: keratoelastoidosis marginalis[2, 3] and focal acral hyperkeratosis.[4, 5] The clinical and histologic differences among these diseases allow their distinction.
Pathophysiology
The cause of acrokeratoelastoidosis (AKE) is not known. Autosomal dominant transmission is common, but the clinical expressions vary widely. Acrokeratoelastoidosis-like lesions on the palms of patients have been noted in association with systemic or localized scleroderma, possibly due to an altered pattern of connective tissue metabolism similar to that of systemic scleroderma.
In 2003, Yoshinaga et al reported on a patient with acrokeratoelastoidosis in association with localized scleroderma.[6]
In 2002, Tajima et al found a high rate of acrokeratoelastoidosis in patients with systemic scleroderma (7 in 26 systemic sclerodermas).[7]
No other reports have confirmed these findings, and the relationship between these two diseases is not conclusive.
A possible linkage to chromosome 2 has also been proposed,[8] but further studies are needed to confirm this hypothesis.
Two cases of unilateral acrokeratoelastoidosis have been reported.[9]
Etiology
No local or systemic causes have been identified. Autosomal dominant transmission is common. Sporadic cases of acrokeratoelastoidosis (AKE) are also described. One report described a patient with endogenous ochronosis showing clinical features similar to acrokeratoelastoidosis.[10]
Epidemiology
Frequency
United States
Acrokeratoelastoidosis (AKE) is rare.
International
The eruption is rare, and when the lesions are few, acrokeratoelastoidosis often remains unnoticed. A survey of 500 consecutive elderly outpatient dermatology patients at the medical school in Puducherry, India found acrokeratoelastoidosis marginalis in 2 (0.9%) females.[11]
Sex
Women appear to be affected more frequently than men.
Age
Acrokeratoelastoidosis is not congenital. It arises at puberty or sometimes later. Some cases have been described in the pediatric dermatologic literature.[12]
Prognosis
Once present, the eruption is stable, with no adverse effects. Recurrences are common.
History
The patient may complain of the gradual onset of small bumps over the margins of the hands and feet. After onset, the eruption remains stable indefinitely. Acrokeratoelastoidosis (AKE) evident as a unilateral sporadic keratosis on the hand and foot has been described in a prepubescent child.[13]
No local or systemic symptoms are associated with acrokeratoelastoidosis. Some reports show acrokeratoelastoidosis in patients with localized or systemic scleroderma, but the relationship between these 2 diseases is not conclusive.
Physical Examination
A cluster of small, discrete, grouped papules characterizes acrokeratoelastoidosis. The papules are usually 2-5 mm in diameter and often occur in a linear distribution. These small round-oval– to rhomboid–shaped yellowish papules are most commonly localized to the palmar surfaces of the hands and, sometimes, on the plantar surfaces of the feet. The margins of both hands and one or both feet are the only areas affected. In rare instances, the lesions spread to the dorsum of the hands, feet, or both. See the image below. Dermatoscopic examination may show yellowish, structureless, linear areas.[14]
View Image | Acrokeratoelastoidosis. Courtesy of William D James, MD. |
The papules resemble plane warts, but they are more keratotic and firm; they do not coalesce. Some translucency is often evident. Occasionally, just a few papules are present. It may rarely appear as plaques.[15]
A case of acrokeratoelastoidosis (AKE) has been seen in association with nail dystrophic changes. Further observations may lead to the definition of a new entity.[16]
Complications
Once present, the eruption is stable, with no adverse effects.
Laboratory Studies
Laboratory studies or other studies are usually not necessary. Biopsy can be helpful for diagnostic purposes and for ruling out other disorders.
Histologic Findings
The typical epidermal features of acrokeratoelastoidosis (AKE) are hyperkeratosis with hypergranulosis, elastorrhexis, acanthosis, and epidermal hyperplasia.[21] Some of these findings may be absent.
The changes in the dermal elastic fibers are characteristic. The number of elastic fibers is often diminished, and the fibers have a discrete-to-intense fragmentation. An elastic fiber stain, such as the Weigert, Verhoeff, or orcein stain, may be useful in demonstrating this fragmentation. Periodic acid-Schiff (PAS) is used to stain carbohydrates, and occasionally, the PAS test is used to rule out other conditions. The cell walls of fungi are rich in carbohydrates, and they stain positively with PAS. PAS does not stain elastic fibers. Acrokeratoelastoidosis has been evaluated ultrastructurally.[22]
Medical Care
Treatment can be challenging.[23] It is not indicated in most patients. Mild keratolytics, such as salicylic acid, occasionally help,[24] but recurrences are common. Use of 10% salicylic acid ointment has been advocated.[25]
Topical retinoids are not effective. The treatment options are not ideal.[26]
The erbium:YAG laser has been effective in improving one patient. No recurrence developed during a follow-up of 6 months.[27]
Author
Robert A Schwartz, MD, MPH, Professor and Head of Dermatology, Professor of Pathology, Professor of Pediatrics, Professor of Medicine, Rutgers New Jersey Medical School
Disclosure: Nothing to disclose.
Coauthor(s)
Enrico Ceccolini, MD, Consulting Staff, Department of Dermatology, University of Bologna; Private Practice, Pesaro, Italy
Disclosure: Nothing to disclose.
Specialty Editors
Michael J Wells, MD, FAAD, Dermatologic/Mohs Surgeon, The Surgery Center at Plano Dermatology
Disclosure: Nothing to disclose.
Warren R Heymann, MD, Head, Division of Dermatology, Professor, Department of Internal Medicine, Rutgers New Jersey Medical School
Disclosure: Nothing to disclose.
Chief Editor
William D James, MD, Paul R Gross Professor of Dermatology, Vice-Chairman, Residency Program Director, Department of Dermatology, University of Pennsylvania School of Medicine
Disclosure: Received income in an amount equal to or greater than $250 from: Elsevier; WebMD.
Additional Contributors
Carrie L Kovarik, MD, Assistant Professor of Dermatology, Dermatopathology, and Infectious Diseases, University of Pennsylvania School of Medicine
Disclosure: Nothing to disclose.
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