Scarlet fever rash usually appears within 24-48 hours after onset of symptoms, although it may appear with the first signs of illness. It is often initially noticed on the neck and upper chest as a diffuse, finely papular, erythematous eruption producing a bright red discoloration of the skin that blanches on pressure. The texture is that of fine sandpaper.
The flexor skin creases, particularly in the antecubital fossae, may be unusually prominent (ie, Pastia lines). The area around the mouth is pale, creating the appearance of circumoral pallor. In severe cases, small vesicular lesions (ie, miliary sudamina) may appear on the abdomen, hands, and feet.
Toward the end of the first week of illness, the rash begins to fade and is followed by a desquamation over the trunk, which progresses to the hands and feet. Typical scarlet fever is not generally difficult to diagnose, but it may be confused with roseola, Kawasaki syndrome, drug eruptions, and toxigenic S aureus infections.
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Invasive soft tissue infection due to Streptococcus pyogenes. This child developed fever and soft-tissue swelling on the fifth day of a varicella-zoster infection. Leading edge aspirate of cellulitis grew S pyogenes. Although the patient responded to intravenous penicillin and clindamycin, operative débridement was necessary because of clinical suspicion of early necrotizing fasciitis.
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Streptococcus group A infections. Beta hemolysis is demonstrated on blood agar media.
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Streptococcus group A infections. M protein.
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Streptococcus group A infections. Erysipelas is a group A streptococcal infection of skin and subcutaneous tissue.
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Streptococcus group A infections. White strawberry tongue observed in streptococcal pharyngitis. Image courtesy of J. Bashera.
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Streptococcus group A infections. Streptococcal rash. Image courtesy of J. Bashera.
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Group A Streptococcus on Gram stain of blood isolated from a patient who developed toxic shock syndrome.
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Streptococcus group A infections. Necrotizing fasciitis of the left hand in a patient who had severe pain in the affected area.
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Streptococcus group A infections. Patient who had had necrotizing fasciitis of the left hand and severe pain in the affected area (from Image 8). This photo was taken at a later date, and the wound is healing. The patient required skin grafting.
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Streptococcus group A infections. Gangrenous streptococcal cellulitis in a patient with diabetes.
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Erythema secondary to group A streptococcal cellulitis.
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Invasive soft tissue infection due to Streptococcus pyogenes. This child developed fever and soft-tissue swelling on the fifth day of a varicella-zoster infection. Leading edge aspirate of cellulitis grew S pyogenes. Although the patient responded to intravenous penicillin and clindamycin, operative débridement was necessary because of clinical suspicion of early necrotizing fasciitis.
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Streptococcus group A infections. Necrotizing fasciitis rapidly progresses from erythema to bullae formation and necrosis of skin and subcutaneous tissue.
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Throat swab. Video courtesy of Therese Canares, MD; Marleny Franco, MD; and Jonathan Valente, MD (Rhode Island Hospital, Brown University).
