The Case of a Scaly Hand: Burrowing into a Diagnosis.

Abstract

A 60-year-old female patient, housewife, belonging to the upper-middle class, hailing from Kerala, India, presented with complaints of itching and scaling, solely involving the left hand for 3 months. She gave a history of aggravation of symptoms after exposure to detergents. There was no contact with other irritants/allergens prior to the onset of the lesions. There were no similar complaints in other family members. She gave a history of applying a topical preparation composed of salicylic acid 3% and clobetasol propionate 0.05% on and off for 1 month with no improvement in lesions. On examination, the patient had scaling, desquamation, and accentuation of skin markings predominantly involving the left palm extending to involve the dorsum of the fingers. The patient also had underlying erythema and mild edema of the affected hand [Figure 1a and b]. Minimal scaling was noted over the right hand.Figure 1: (a) Scaling, desquamation, accentuation of skin markings over the left palm with erythema and mild edema. (b) Scaling, desquamation over the dorsum of fingers of the left hand with mild edemaThe lesions were nontender. No nail changes were seen. Soles were normal. No other lesions were present on the body. With a provisional diagnosis of Tinea manuum and hand eczema, 10% potassium hydroxide mount was done to arrive at a final diagnosis. The image we found through the lens caught us by surprise. We expected to find fungal hyphae, but surprisingly we found an eight-legged arthropod, the Sarcoptes scabiei mite with scybala! [Figure 2].Figure 2: 10% potassium hydroxide mount showing mite of Sarcoptes scabiei and scybalaThe patient was treated with permethrin 5% cream and antihistamines. The patient was reviewed back after 2 weeks with complete improvement in her symptoms and lesions [Figure 3].Figure 3: After treatment, the scaling and desquamation over the left hand has resolvedScabies, a parasitic infestation of the skin is caused by the mite Sarcoptes scabiei.[1] Burrows are the primary lesions in scabies. Secondary lesions include papules, vesicles, pustules, and excoriations.[2] The typical distribution of lesions includes web spaces of fingers, the wrists, axillae, groins, buttocks, genitals, and the breasts in women.[3] Scabies can also manifest with atypical morphological forms such as bullae, crusting, ecchymoses, urticaria, and eczema. Scabies surrepticius is a term that has been proposed to describe the atypical morphological presentations of this infestation.[4] Wilson et al.[5] reported an atypical appearance of scabies in the form of papulosquamous lesions among inmates of a nursing home. Usually, in chronic infestation and use of long-term topical steroids, eczematous lesions may be the presenting picture as was in our case.[6] We would also like to emphasize the predominantly unilateral involvement of the left hand in this patient. Such atypical presentations often confound the diagnosis of scabies and hence this case emphasizes the importance of potassium hydroxide mount, a very simple but essential tool to confirm the diagnosis in doubtful cases. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.