Rashes

Question 1

flu-like prodrome–> cheek rash followed by generalized erythematous, reticulated or lace-like rash on the trunk and extremities. Mucous membrane involvement is not typical.

Answer 1

Erythema infectiosum, or fifth disease: caused by a parvovirus B19 infection

Question 2

A generalized macular exanthem…rash appears after a high fever resolves, at about 3-5 days.

Palpebral conjunctivitis and palatoglossal ulcerations may occur.

Answer 2

Roseola: most typically seen in infants with human herpesvirus 6 infection.

Question 3

characterized by a diffuse maculopapular rash, prominent cervical lymphadenopathy, mild sore throat, and low-grade fever +/- arthralgias or arthritis, typically lasts only 3 days….

Answer 3

Rubella… closely resembles measles. Outbreaks are seasonal, commonly occurring in the spring, though rubella is infrequently seen in the United States due to use of the MMR vaccine.

Question 4

cough, runny nose,red conjunctivas, high fever, mucosal papules: fever peaks with erythematous, macular rash.

Answer 4

Rubeola, or measles

characterized by a prodrome of the “3 Cs:” Cough, Coryza, and Conjunctivitis, accompanied by a high fever and more toxicity than seen in rubella. The febrile peak coincides with the peak of the diffuse, erythematous, macular rash. The illness typically lasts approximately 5 days.

The mucosal lesions of measles include conjunctivitis and oral Koplik spots (whitish-bluish papules on an erythematous base found on the buccal mucosa by the molars), which are diagnostic.

Question 5

manifests with the target lesions, macular or bullous, commonly affects palms, soles, and extensor surfaces. . Lesions have 3 zones of color: a red central zone, surrounded by a pale ring, rimmed by a zone of erythema. Mucous membrane involvement.

Answer 5

erythema multiforme (EM): thought to be a hypersensitivity reaction to a drug, drug metabolite, or infectious trigger.

Infections, particularly herpes simplex virus and Mycoplasma pneumoniae, are commonly implicated in EM, while drugs such as sulfonamides, aminopenicillins, and antiepileptics have a greater association with SJS and TEN. In all forms, patients may experience a nonspecific flu-like prodrome.

Question 6

significant mucosal involvement should suggest

Answer 6

Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN).

SJS is an immune-mediated hypersensitivity reaction with <10% body surface area (BSA) involvement, while TEN involves >30% BSA;

Question 7

confluent, white, non-scaling, edematous papules coalescing into plaques

Answer 7

urtical wheel

Question 8

sharply demarcated, erythematous plaques covered with silvery scale

Answer 8

psoriasis

Question 9

superficial ulcer with clean base and indurated margins

Answer 9

syphilis

Question 10

erythematous patch with annular clearing and central hyperpigmentation

Answer 10

lyme disease

Question 11

ovoid, erythematous, scaly rash on trunk or extremities –> KOH prep shows hyphea

Answer 11

tinea corporis

Question 12

pityriasis rosea vs guttate psoriasis

Answer 12

pityriasis has herald patch; guttate does not, and is associated with strep pharyngitis infection

Question 13

ovoid, erythematous, scaly rash on trunk or extremities –> KOH prep is sterile

Answer 13

pityriasis rosea