Given the extremely broad differential diagnosis, the presentation of a patient with fever and rash often poses a thorny diagnostic challenge for even the most astute and experienced clinician. Rapid narrowing of the differential by prompt recognition of a rash’s key features can result in appropriate and sometimes life-saving therapy. This atlas presents high-quality images of a variety of rashes that are associated with fever, most of which have an infectious etiology.
A. Erythema leading to “slapped cheeks” appearance in erythema infectiosum (fifth disease) caused by parvovirus B19. B. Lacy reticular rash of erythema infectiosum. (Panel A reprinted from K Wolff, RA Johnson: Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology, 6th ed. New York, McGraw-Hill, 2009.)
Koplik’s spots, which manifest as white or bluish lesions with an erythematous halo on the buccal mucosa, usually occur in the first 2 days of measles symptoms and may briefly overlap the measles exanthem. The presence of the erythematous halo (arrow indicates one example) differentiates Koplik’s spots from Fordyce’s spots (ectopic sebaceous glands), which occur in the mouths of healthy individuals. (Courtesy of the Centers for Disease Control and Prevention.)
In measles, discrete erythematous lesions become confluent on the face and neck over 2–3 days as the rash spreads downward to the trunk and arms, where lesions remain discrete. (Reprinted from K Wolff, RA Johnson: Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology, 5th ed. New York, McGraw-Hill, 2005.)
In rubella, an erythematous exanthem spreads from the hairline downward and clears as it spreads. (Courtesy of Stephen E. Gellis, MD; with permission.)
Exanthem subitum (roseola), caused by human herpesvirus 6, occurs most commonly in young children. A diffuse maculopapular exanthem follows resolution of fever. (Courtesy of Stephen E. Gellis, MD; with permission.)
Erythematous macules and papules are apparent on the trunk and arm of this patient with acute HIV infection. (Reprinted from K Wolff, RA Johnson: Color Atlas and Synopsis of Clinical Dermatology, 5th ed. New York, McGraw-Hill, 2005.)
This exanthematous, drug-induced eruption consists of brightly erythematous macules and papules, some of which are confluent, distributed symmetrically on the trunk and extremities. Ampicillin caused this rash. (Reprinted from K Wolff, RA Johnson: Color Atlas and Synopsis of Clinical Dermatology, 5th ed. New York, McGraw-Hill, 2005.)