Purpuric Rash After Upper Respiratory Tract Infection

Two 7-year-olds show the purpuric rash of the lower body and legs that is typical of Henoch-Schnlein purpura. This disease is a vasculitis that chiefly affects small vessels of the skin, joints, gastrointestinal tract, and kidney.

Drs Robert P. Blereau, Anthony J. Saleme, and Murali Davuluri of Morgan City, La, write that their patient described her rash as “red dots” that appeared on her legs and then progressed over 5 days to swollen ankles, purpura of both feet, and bruises on her thighs (Figures A, B, and C). Her temperature was 38.9°C (102°F), and she complained of general achiness and bilateral loin pain. Three weeks before the rash's onset, this young girl had been treated for a streptococcal infection of the pharynx; but when evaluated for the rash, her complete blood cell count, including platelets, and urinalysis were normal.

Drs Alexander K. C. Leung and Helen Y. H. Cho of Calgary, Alberta, report that their patient complained of abdominal pain and bilateral knee pain 2 days before the purpuric rash erupted on his lower extremities and buttocks (Figures D and E). His temperature was normal. Laboratory results included white blood cell count, 11.9 × 109/L; platelet count, 270 × 109/L; and hemoglobin, 120 g/dL. Results of the initial urinalysis were normal, but a repeated urinalysis performed 24 hours later showed numerous red blood cells and red blood cell casts.

Henoch-Schnlein purpura is characterized by nonthrombocytopenic purpura, arthritis or arthralgia, abdominal pain, and glomerulonephritis,¹ add Drs Leung and Cho. The rash is usually found on the lower extremities and buttocks because it is gravity- or pressure-dependent.²

Drs Blereau, Saleme, and Davuluri tell us that Henoch-Schnlein purpura is a leukocytoclastic vasculitis believed to be secondary to IgA-immune complexes deposited in blood vessel walls mainly in the skin, gastrointestinal tract, and kidneys. It occurs most commonly in children between the ages of 2 and 10 years and usually develops 1 to 3 weeks after a streptococcal or viral upper respiratory tract infection. The disease generally is benign and self-limited, with the degree of renal involvement determining the prognosis. Corticosteroids may be used if the symptoms warrant treatment. Drs Blereau, Saleme, and Davuluri prescribed a 2-week course of tapering prednisone, and the young girl's condition progressively improved.

REFERENCES:1.Robson WL, Leung AK. Henoch-Schnlein purpura. Adv Pediatr. 1994;4:163-194.
2. Robson WL, Leunk AK, Lemay M. The pressure-dependent nature of the rash in Henoch-Schnlein purpura. J Singapor Paediatr Soc. 1992;4:230-231.