An 11-year-old girl was admitted with backpain, weight loss, fatigue and behavioural disturbances, starting seven weeks before admission. Physical examination showed acrodynia, tremor, cachexia, hypertension and extensive gingival ulceration. Routine laboratory tests were normal, except for a CRP of 98 mg/l. Screening tests for recreational drugs as well as antibody assays for HIV, hepatitis B and borrelia burgdorferia were negative. Chest X-ray, brain CAT and MRI scan were all normal. Lumbar puncture didn't show any abnormalities. Eventually a 24-hour urine test confirmed the diagnosis that was suspected by further questioning.