The patient is a 25-year-old male with Down's syndrome who was hospitalized for 10 days due to a macular popular rash on the thorax, abdomen and extremities, with fever, abdominal pain and nausea. The patient had a history of celiac disease and hypothyroidism that were under control and had used allopurinol 20 days earlier. Upon examination the patient had a macular and popular rash on the neck, thorax, abdomen and extremities, as well as hand and feet edema (Figs. 1 and 2). The patient had no synovitis or other findings.

Fig. 1.

Rash and edema on the extremities.

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Fig. 2.

Diffuse rash of the thorax and neck.

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Laboratory: leukocytosis 15800 (990 eosinophils), aspartate-transaminase 138, alanine-aminotransferase 300. Renal function, immunology tests and serology for exanthematic diseases were normal. An abdominal ultrasound showed mild liver and spleen enlargement. Chest and abdomen x rays were normal. A punch biopsy of the skin lesion showed evidence of a spongiotic reaction to drugs. The patient had used allopurinol 20 days earlier, complying with two major criteria (skin rash and liver affection) and 3 minor criteria (leukocytosis, fever, eosinophilia) of those proposed by Zinger and Wallace for allopurinol hypersensitivity. Treatment with IV liquids, steroids and antihistamines was started (allopurinol had been suspended a week prior), with excellent clinical progression, remission of fever and the rash and a normalization of liver enzymes.

Drug related eosinophilia and systemic symptoms (DRESS), in this case allopurinol, is a type IV late hypersensitivity reaction that presents in approximately 2% of patients after 2–4 weeks of treatment.

This is the favored term to refer to currently describe a drug reaction. Although most generally have a favorable outcome, mortality may reach 25%, fundamentally due to liver or renal damage or severe sepsis.

Older patients, with renal failure, using thiazides and Asians seem to have a greater predisposition to developing DRESS.

Our case was a young male patient with Down's syndrome with a diffuse rash and fever, initially leading us to the diagnosis of measles. The fact that he had received treatment with allopurinol due to a prior asymptomatic hyperuricemia made it possible to suspect the drug related origin of his disease.

The authors declare no conflict of interest.