Aquagenic Syringeal Acrokeratoderma: Report of a Case with Dermoscopic Findings.

Sir,

Aquagenic syringeal acrokeratoderma (ASA) is a rare disorder that is characterized by symmetrical, edematous, white and translucent papules and plaques. It develops after brief exposure to water. The diagnosis of ASA is generally made based on patient's history, clinical and histopathological examination.[1] Dermatoscopic findings of ASA have been reported in only two cases previously.[23] We report ASA in a teenage girl with dermoscopic features.

A 15-year-old girl presented with a 1-year history of asymptomatic, symmetrical, and white lesions located on her palms. These lesions occurred within minutes of exposure to water or sweat and resolved within 20 min after drying her hands. The patient also reported hyperhidrosis of the palms. On dermatological examination, her palms were macerated, when she soaked her hands in water for several minutes, small white papules coalescing into plaques appeared [Figure 1]. She had no history of drug use, contact, or atopic diathesis. On dermoscopic examination, sweat duct pores became larger when compared with a normal-appearing area on the thenar region [Figure 2a]. Furthermore, tripe-like structures were seen on involved areas [Figure 2b]. After immersion in water, a punch biopsy was performed on the right palm. Histopathologic examination revealed hyperkeratosis, acanthosis, and dilatation of the eccrine ducts in the epidermis [Figure 3]. Based on the clinical, dermoscopic, and histopathological findings, we made the diagnosis of ASA. Her symptoms were regressed by 19% aluminum hydroxychloride cream application for 3 months.

Figure 1

Appearance of small white papules coalescing into plaques on the palmar region of the right hand

Figure 2

Dermoscopic images of the lesion. (a) Dermoscopic observation revealed a marked dilatation of sweat duct puncta and (b) tripe-like structures

Figure 3

Hyperkeratosis, acanthosis, and dilation of the eccrine ducts in the epidermis (H and E, ×200)

The exact pathogenesis of ASA remains unclear. Several hypotheses have been proposed to explain the pathogenesis - structural or functional defects of stratum corneum during adolescence, primary disease of the sweat ducts, increased sodium concentration in the skin, thereby increasing the water-retention capacity of stratum corneum or a reaction to drugs such as rofecoxib, celecoxib, and aspirin.[45] The reported associations included cystic fibrosis (CF), asthma, allergic rhinitis, urticaria, palmar erythema, and malignant melanoma.[5] In our patient, she had no history of CF, so we did not perform sweat chloride test. Palmar/plantar hyperhidrosis has also been described in a subset of cases with ASA.[2] In our patient, there was no associated disorder except palmar hyperhidrosis.

Treatment modalities include 20% aluminum chloride solution, botulinum toxin injections, iontophoresis, antihistamines, pomade containing 5% salicylic acid, a mixture of mometasone furoate and petroleum jelly, and a cream containing 20% urea.[14] Our patient used 19% aluminum hydroxychloride cream for 3 months. Her lesions regressed after 3 months, but when she stopped the use of the cream her symptoms recurred.

Dermatoscopic features of the lesion have been defined in two previous reports as per our knowledge.[23] In these reports, comparison of marked enlargements of the sweat duct puncta and unaffected palmar regions were demonstrated by dermoscope. These findings reflect the dilated and tortuous acrosyringium.[2] Our dermoscopic findings were compatible with these reports. In addition, whitish, pebbly, papular thickening of the palms was seen on dermoscopic examination. We refer to this finding as tripe-like structure because of similarity of tripe.

The diagnosis of ASA is generally made based on patient's history and clinical examination.[1] We propose dermoscopy of ASA to assist in the diagnosis of the disease, by highlighting the enlargements of sweat duct puncta.

ASA is known as a rare disorder, but it may be more frequent than thought. Dermoscopy, noninvasive, easy and useful method, may provide a rapid and accurate diagnosis of unnoticed ASA.

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Conflicts of interest

There are no conflicts of interest.