(Photo contributor: Binita R. Shah, MD)
*The authors acknowledge the special contributions of Vikas S. Shah, MD, and Binita R. Shah, MD, to prior edition.
STREPTOCOCCAL PHARYNGITIS AND SCARLET FEVER
Streptococcal pharyngitis, commonly referred to as “Strep throat” is acute tonsillopharyngitis most often caused by Streptococcus pyogenes (group A β-hemolytic streptococci [GABHS]), and occasionally by other serogroups, such as C and G. Streptococcal pharyngitis is seen among schoolchildren (5–15 years) with a peak incidence during the first few years of school. The incubation period is 2 to 4 days. Presenting symptoms are abrupt onset with high fever, sore throat, pain on swallowing, malaise, headache, and abdominal pain. The pharynx, palate, and uvula are erythematous and in most instances, the palate and uvula will be edematous and covered with petechiae. The tonsils are enlarged with patches of a gray-white exudate giving a “strawberry” appearance (intensity of exudates ranges from absent in mild cases to a distinct membrane covering the entire pharynx in severe cases). Tender anterior cervical lymphadenopathy at the angles of the mandibles is palpable.
Scarlet fever rash may appear 12 to 24 hours after the onset of fever. The patient’s forehead and cheeks are flushed with circumoral pallor. Patients often have a rash characterized by tiny papules that appear like a “sunburn with goose pimples,” sandpaper texture, and blanches with pressure. This rash begins in the axilla, groin, and neck and generalizes, sparing the palms, soles, and face, within 24 hours. Other findings include strawberry tongue, exudative tonsillopharyngitis, and Pastia sign (an accentuation of the rash in skin folds with fine line of petechiae). Desquamation may occur after 7 to 10 days and usually continues for 2 to 3 weeks, but can last up to 2 months. When desquamation occurs, it begins as fine flakes on the face, then proceeds over the trunk, hands, and feet. The extent and duration of desquamation are directly related to the intensity of the rash. Scarlet fever rash is caused by 1 or more of several erythrogenic exotoxins produced by GABHS strains and occurs in children who lack immunity to the exotoxin. The portal of entry is the oropharynx in the majority of cases and rarely a surgical wound (surgical scarlet fever). Most cases occur in children between 2 and 8 years of age, typically in winter and early spring.
Exudative Tonsillopharyngitis. Exudative tonsillopharyngitis in an adolescent presenting with high fever, sore throat, and tender anterior cervical adenopathy and a throat culture positive for GABHS. Intensity of exudates can be absent in mild cases to formation of a membrane covering the entire pharynx in severe cases. (Photo contributor: Mark Silverberg, MD.)