Scarlet Fever and Group A Streptococci Infection

This 6-year-old boy was brought to his physician for evaluation of a rash. The child had been running a fever and, for the past 48 hours, had been complaining of a sore throat, headache, and abdominal pain.

The patient had red tonsils with exudates, petechiae on the soft palate, a red tongue and lips, and bilateral submandibular lymphadenitis. He also had an erythematous, pinhead-sized papular rash on his chest, abdomen, and back.

Results of a rapid streptococcal antigen test on the throat swab were positive. Linda S. Nield, MD, of West Virginia University and Deepak Kamat, MD, PhD, of Wayne State University made the diagnosis of scarlet fever secondary to a group A streptococci (GAS) infection. The patient was treated with penicillin; his rash resolved gradually with peeling. Patients with scarlet fever usually complain of fever, sore throat, headache, abdominal pain, vomiting, myalgias, and rash. The rash appears as very fine, erythematous papules on the upper trunk and extremities that may be more prominent in the flexural regions. Facial erythema with perioral pallor also may be present. Desquamation-particularly of the hands and feet-is a possibility later in the course of this illness. Oral findings include an erythematous pharynx, exudative tonsils, a strawberry tongue, and palatal petechiae. Tender and enlarged cervical lymph nodes are also typical.

Scarlet fever results from a GAS infection of the throat or, rarely, of the skin. These strains of bacteria produce one or more erythrogenic exotoxins that cause the characteristic skin findings.¹

Several serious conditions can present with many of the features found in patients with scarlet fever. These include Kawasaki disease, toxic shock syndrome, infectious mononucleosis, drug rash, serum sickness, Stevens-Johnson syndrome, and enteroviral infections. The presence of typical physical findings and a positive rapid streptococcal antigen test or a throat culture positive for GAS confirm the diagnosis of scarlet fever.

Treatment is necessary to prevent both nonsuppurative (rheumatic fever, glomerulonephritis) and suppurative (lymphadenitis, peritonsillar abscess) complications of the streptococcal infection. Oral penicillin or intramuscular benzathine penicillin remains the first-line antibiotic choice; erythromycin is an option if the patient is allergic to penicillin.² Supportive care can be provided for the throat pain and rash; parents need to be warned that the skin may desquamate.

REFERENCES:1. Group A streptococcal infections. In: Pickering LK, ed. Red Book: 2003 Report of the Committee on Infectious Diseases. 26th ed. Elk Grove Village, Ill: American Academy of Pediatrics; 2003:573-584.
2. Bisno AL, Gerber MA, Gwaltney JM Jr, et al. Practice guidelines for the diagnosis and management of group A streptococcal pharyngitis. Infectious Diseases Society of America. Clin Infect Dis. 2002;35:113-125.