Mechanic’s Hands and Hiker’s Feet in a Child with Juvenile Dermatomyositis Overlap Syndrome

Abstract

A 10-year-old boy presented with a history of rashes on his palms and soles for 1 year. He had difficulty in walking, climbing stairs, and worsening of skin lesions for 2 months. On examination, he had hyperkeratotic, scaly lesions with fissures on his hands and feet suggestive of mechanic’s hands [Figure 1a] and hiker’s feet [Figure 1b]. Fingernails appeared dystrophic with pitting [Figure 2a]. Musculoskeletal examination showed severe proximal muscle weakness with a positive Gower’s sign. His investigations revealed Hemoglobin (Hb) – 13.4 g/dl (12–15), white blood cell count – 13,300/cumm (4000–11,000), neutrophil – 61% (45–70), lymphocyte – 28% (20–40), platelets – 3.65/cumm (1.5 to 4.5), erythrocyte sedimentation rate (ESR) – 42 mm/h (4-–12), C-reactive protein (CRP) – 2 mg/L (<5), aspartate transaminase (AST) – 435 U/L (8-48), alanine transaminase (ALT) – 1753(7-55), creatine phosphokinase (CPK) – 5336 IU/L (20-200), and lactate dehydrogenase (LDH) – 1536 U/L (110-295); renal functions were normal. Antinuclear antibody (ANA) was positive by indirect immunofluorescence method 1:320, 3 +. Antibody screen for myositis profile revealed strong positivity for PM-Scl antibodies. Magnetic resonance imaging of the thighs revealed altered signal intensity within muscles suggestive of inflammatory myositis and high-resolution computed tomography of the chest revealed fibrosis in the anterior segment of the right middle lobe and posterior basal segment of the right lower lobe. He was diagnosed with dermatomyositis overlap syndrome and commenced on steroids, monthly intravenous (IV) cyclophosphamide, weekly subcutaneous methotrexate, and sunscreen. With treatment, there was improvement in muscle strength, complete resolution of skin changes; with nails initially showing demarcation of area of normal growth from the dystrophic part [Figure 2b] and later completely normal nails [Figure 2c].Figure 1: (a) Mechanic’s hands, (b) Hiker’s feetFigure 2: (a) dystrophic nails with pitting, (b) post treatment resolution of skin changes and nails showing demarcation between area of normal growth and dystrophic part, (c) complete resolution of skin and nail changesThe term mechanic’s hands is used to describe hyperkeratotic lesions that maybe present in the hands and fingers of patients with inflammatory myositis.[1] Equivalent lesions present in the feet were later termed hiker’s feet.[2] These findings are mostly associated with the presence of anti-Jo-1 synthetase antibody and rarely in dermatomyositis overlap syndromes.[3] The disease course tends to be chronic and may require the administration of high-dose steroids, followed by a taper, disease-modifying agents, and/or rituximab. Declaration of consent The authors certify that they have obtained all appropriate consent forms, duly signed by the parent(s)/guardian(s) of the patient. In the form, the parent(s)/guardian(s) has/have given his/her/their consent for the images and other clinical information of their child to be reported in the journal. The parents understand that the names and initials of their child/children 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.