Kawasaki Disease (see Chapter 101 Rheumatologic Emergencies ) Kawasaki disease can present with a wide variety of rashes, including morbilliform and urticarial Conjunctivitis, when present, is unique in that it is nonexudative with limbal sparing Other dermatologic manifestations include red cracked lips, strawberry tongue, and erythematous oropharynx, and erythema, swelling, and/or induration of peripheral extremities The most commonly associated rash is a generalized exanthem with raised erythematous plaques; however, the rash may also present with an erythematous maculopapular, morbilliform, scarlatiniform, or erythema marginatum–like pattern Peeling in the diaper/groin area is also frequently observed early The exanthem may be fleeting or persist for to days During the later stages of the acute phase, periungual desquamation and peeling of the palms, soles, or perineal area develop Measles (Rubeola) Measles was one of the most common viral exanthems before the measles vaccine It is now on the rise again because of increased opting out of vaccinations for children The incubation period is 10 to 14 days after direct contact with droplets from an infected person In its classic form, measles has a highly characteristic natural history Two to days after the onset of the prodromal symptoms of cough, coryza, conjunctivitis, and fever, Koplik spots occur in the mouth, followed 12 to 24 hours later by the cutaneous exanthem Most typically, Koplik spots appear as pinpoint white lesions on a red base on the buccal mucosa adjacent to the molars; however, they may be seen on any of the mucosal surfaces of the oral cavity except the tongue The measles exanthem begins on the head as reddish maculopapules and spreads caudally during the next to days Within to days of its appearance, the discrete maculopapular lesions coalesce to produce the confluent phase of the rash Hence, within to days of onset, the rash on the face becomes confluent, whereas the rash on the lower extremities still consists of individual maculopapules Modified measles occurs in children who have received serum immunoglobulin after exposure to measles Measles may still occur, but the incubation period may be delayed up to 21 days The symptoms, although following the usual progression, will be milder A faint rash and mild febrile illness may occur to 10 days after immunization with the live attenuated measles vaccine Rocky Mountain Spotted Fever