Aim: To describe the incidence, clinical presentation and paraclinical findings in childhood sarcoidosis in Denmark, 1979-1994.
Methods: Patients (n = 5536) with a diagnosis of sarcoidosis were drawn from the nationwide Patient Registry; 81 patients were < or = 15 y of age. The diagnosis of sarcoidosis was reconfirmed in 48/81 (59%) patients. In 35/48 (73%) patients, diagnosis was verified by histology, and in 13 it was substantiated by paraclinical/clinical findings.
Results: The series comprised 26 boys and 22 girls (male/female ratio 1.18). Median age at diagnosis was 13 y (range 0.7-15). In 1979-1994 the incidence was 0.29 per 100000 person-years < or = 15 y of age. The incidence was 0.06 in children < or = 4 y of age and increased gradually with age to 1.02 in children aged 14-15 y. General malaise, fever, weight loss, abdominal discomfort, respiratory symptoms, lymphadenopathy and central nervous system symptoms were common; 31% of patients had erythema nodosum, 12.5% sarcoid skin lesions, 25% uveitis/iridocyclitis and 4.2% sarcoid arthritis. Chest X-rays were normal (stage 0) in 10% of patients, and showed pulmonary infiltrates stage I in 71%, stage II in 8.3% and stage III in 8.3%. Lung function tests were examined in 13 patients: 50% had decreased FEV1 and vital capacity, 80% decreased DLCO. Haemoglobin values were normal. Some patients had mild leukopenia, some moderate leukocytosis and a few had moderate eosinophilia. Erythrocyte sedimentation rate was elevated in 40% of the patients. Plasma calcium was elevated in 30% of the patients; 4 patients had severe hypercalcaemia and elevated plasma creatinine, and 1 patient had nephrocalcinosis. Serum angiotensin-converting enzyme was elevated in 55% of the patients. Liver function tests were normal with no sarcoid hepatitis. Urinary examination (glucose, albumin, haemoglobin) was normal in 96% of the patients; the patient with nephrocalcinosis had albuminuria and haematuria.
Conclusion: The incidence of sarcoidosis in Danish children is low and increases with age. Sarcoidosis in young children may present clinical features that are different from the appearance of those in older children and often constitute a diagnostic challenge. In older children, the clinical appearance has many features in common with the presentation in adults.