'Hand-in-the-Bucket' Sign: A Clue to Aquagenic Syringeal Keratoderma.

Sir,

A 41-year-old woman presented with itching, wrinkling, and thickening of bilateral hands following exposure to water for the past 18 months. No history of hyperhidrosis, atopy, any systemic illness, drugs, or any relevant family history was elicited. Examination revealed bilaterally symmetrical, accentuated wrinkling of dorsa of hands and palms with distorted dermatoglyphics [Figure 1a and 1b]. A water-immersion test was done and after 5 min, rugated plaques with translucent whitish papules and prominent eccrine pores were noted, indicating a positive “hand-in-the-bucket” sign [Figure 1c and 1d]. Histopathology of a palmar papule showed compact hyperkeratosis, spongiosis of stratum corneum, hypergranulosis, mild-to-moderate acanthosis, dilated and tortuous corneal and epidermal acrosyringium, and mild edema [Figure 2a and 2b]. Based on clinical and histological findings, a diagnosis of acquired aquagenic syringeal acrokeratoderma was made. The patient was counseled about the benign nature of the disease and put on topical aluminum chloride hexahydrate. Six months of follow-up showed moderate patient satisfaction.

Figure 1

(a-b) Bilaterally symmetrical, accentuated wrinkling of dorsa of hands and palms with distorted dermatoglyphics. (c-d) After 5 min of immersion in water, rugated plaques with translucent whitish papules, prominent eccrine pores were seen

Figure 2

Skin biopsy specimen from a palmar papule revealed (a) compact hyperkeratosis with corneal spongiosis, hypergranulosis and mild-to-moderate acanthosis and dermal edema (hematoxylin & eosin, 10×), (b) compact hyperkeratosis with dilated acrosyringia both in the stratum corneum and epidermis (hematoxylin & eosin, 40×)

Aquagenic syringeal acrokeratoderma (ASA), also reported in the literature by names such as aquagenic palmoplantar keratoderma, aquagenic wrinkling of the palms, and transient reactive papulotranslucent keratoderma is a water-induced dermatosis. It is characterized by symmetrical, translucent to white papules and/or plaques that become accentuated on exposure to water. Although exact pathophysiology remains unclear,[1] various hypotheses put forward are aberration of the sweat duct, transient structural or functional alteration of stratum corneum resulting in increased water absorption, abnormal cutaneous electrolyte fluctuation, and nerve dysfunction.[2] Drug-induced ASA, reported with COX-2 inhibitors, gabapentin, aspirin, acetaminophen, ascorbic acid, clarithromycin, is believed to be due to dysregulation of aquaporins and increased sodium retention in the epidermis.[34] The disease has a predilection for females, and preferentially involves palms and fingers. The “hand-in-the-bucket” sign is a clinical diagnostic clue of ASA and can be demonstrated when patients submerge their hands in water to demonstrate the papules. The time latency required for the appearance of lesions after contact with water is around 2 to 10 min.[2] Histopathologically, a mild orthokeratotic hyperkeratosis and dilated eccrine ducts are seen.[2] The closest differential is hereditary papulotranslucent acrokeratoderma (HPA), where white papules appear on the margins of palms and soles around puberty, associated with fine-textured scalp hair and an atopic diathesis. However, HPA shows focal hyperkeratosis, acanthosis, and normal eccrine ducts in histopathology.[2] Treatment modalities tried for ASA include aluminum chloride hexahydrate, keratolytics, botulinum toxin, iontophoresis, and endoscopic thoracic sympathectomy.[2] Reported associations of ASA include hyperhidrosis, palmar erythema, allergic rhinitis, bronchial asthma, and most importantly cystic fibrosis.[34]

Aquagenic syringeal acrokeratoderma is often underdiagnosed owing to its mild and transient clinical presentation. There is a need for more focus on this rare and interesting dermatosis.

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