Pebbling of skin: Cutaneous marker of Hunter syndrome

Indian Dermatology Online Journal | January-February 2017 | Vol 8 | Issue 1 62 Sir, Hunter syndrome or mucopolysaccharidoses type II (MPS II) belong to a group of lysosomal storage disorder caused by the deficiency of iduronate‐2‐sulfate leading to decreased degradation of mucopolysaccharides. It is characterized by accumulation of glycosaminoglycans within lysosomes of various organs including the skin. It is inherited as an X‐linked recessive disorder, and hence, seen only in males. Hunter syndrome is the only type of MPS that has distinctive skin lesions described as “pebbling” of skin.[1] We describe this case of Hunter syndrome to highlight this distinctive skin lesion that serves as a cutaneous marker in early diagnosis. A 7‐year‐old male term child, born of nonconsanguineous marriage by normal vaginal delivery, presented with asymptomatic skin colored raised lesions on the upper back, chest, and arms from past 4 years. The lesions first appeared on the upper back and slowly progressed over the years to involve the chest and both arms. Developmental milestones were delayed with speech abnormalities. He had normal intelligence. The child had recurrent upper respiratory tract infection and was operated for umbilical hernia 2 months back. Family history was noncontributory. General physical examination revealed short stature, coarse facial features, thick eyebrows, puffy eyelids, depressed nasal bridge, wide nostrils, thick lips, protuberant abdomen, broad hands, stubby fingers, and claw‐like contractures of the distal interphalangeal joints [Figure 1]. He had contractures of elbow joints with widening of bilateral wrist. Cutaneous examination showed multiple, firm skin‐colored papules and nodules measuring 0.5 cm × 1 cm to 1 cm × 2 cm presenting bilaterally and symmetrically in a reticular pattern over the scapulae, posterior axillary line, lateral aspect of upper arms, and pectoral region, giving the appearance of pebbled skin [Figure 2a‐d]. Hypertrichosis was seen on the trunk and extremities. Systemic examination showed hepatosplenomegaly. Systolic murmur was present. Ophthalmological examination was normal. Complete blood counts and renal and liver function test were normal. 2D echocardiography revealed moderate aortic regurgitation, mild mitral regurgitation, and left ventricular hypertrophy with normal left ventricular function. Nerve conduction study showed motor axonal neuropathy of bilateral median nerves. Lateral skull radiography showed J‐shaped sella turcica with thickened skull. Hand radiography showed proximal tapering of metacarpal bones. Enzyme analysis showed deficiency of iduronate sulfatase, 0.04 nmol/4 h/mg (Normal values: 15‐57 nmol/4 h/mg) confirming the diagnosis of Hunter syndrome (Type B). Parents did not give consent to do a skin biopsy, hence, it was not performed. Pebbling of skin: Cutaneous marker of Hunter syndrome