Farber disease: report of three cases with joint involvement mimicking juvenile idiopathic arthritis.

Farber disease is a rare recessive autosomal disorder presented with three main features of joint involvement, subcutaneous nodules and hoarseness. Hereby we describe three new cases of Farber disease. All three cases were first misdiagnosed as juvenile idiopathic arthritis (JIA) due to the presentation of joint swelling. Addition of hoarseness and subcutaneous nodules to the initial joint swelling questioned the diagnosis of JIA and further evaluations led to the diagnosis of Farber disease. The first case was a 4-year old girl in whom a novel genetic mutation in ASAH1 gene was found. The second patient was a 4-year old girl presented with joint swelling at 7 month of age. The third patient was a 9-month boy complicated with severe respiratory distress. All patients were treated with symptomatic and supportive care. Two cases died due to respiratory ailure and infection, but one patient follow up for 2 years after diagnosis. Farber disease should be considered as differential diagnosis in children with early onset of poly articular involvement with subcutaneous nodules and/or hoarseness.

Mucopolysaccharidosis Type I in Children, a Forgotten Diagnosis Responsible for Undiagnosed Musculoskeletal Complaints: Report of Two Cases.

Mucopolysaccharidoses (MPS) are a subgroup of lysosomal storage disorders. The underlying mechanism of MPS disorders are deficiency in specific enzymes which leads to accumulation of partially degraded glycosaminoglycans (GAGs) in various tissues. A wide variety of manifestations are reported but musculoskeletal complaints are common among them. In milder forms of MPS, musculoskeletal complaints are presenting symptoms. Delays in diagnosis due to unspecific and mild symptoms is common. Misdiagnosis of MPS as juvenile idiopathic arthritis and other inflammatory arthritis disorders is frequent. Early diagnosis and treatment prevents irreversible cellular damages and is a key factor in efficacy of enzyme replacement therapy. In this study we described two MPS patients with musculoskeletal complaints who were not diagnosed for a period of time. Although musculoskeletal manifestation are common in a variety of clinical conditions, their presence at low ages or co-occurrence of other manifestations (such as cardiac, respiratory, neurologic, etc.) in multiple systems should prompt evaluation of patients for MPS and other metabolic disorders. The rheumatologists' awareness on MPS should be promoted to achieve timely diagnosis and subsequent early treatment.