Exanthems

Question 1

Classic exanthem clinical picture

Answer 1

Maculopapular eruption which initally does not scale

If oral findings: enanthems

Question 2

Distinguishing features of measles

Answer 2

Morbilliform, itchy, begins on head and neck and spreads quickly, onset of rash a few days after C,C,Cs & fever start, +/- Koplick spots on buccal mucosa

Question 3

Distinguishing features of Rubella

Answer 3

milder sx than measles but similar rash (resolves in 3-4 days)

Question 4

Distinguishing features of Roseola infantum

Answer 4

Very high temp, followed by pink eruption that starts on trunk and spreads to face and extremities. Cause HHV6

Question 5

Distinguishing features of Erythema infectiosum (5th)

Answer 5

Slapped cheek 2-4 days before generalized, livedo-pattern rash which starts on extremities and spreads centrally. Cause ParvoB19

Question 6

Distinguishing features of Mono

Answer 6

Rash w/in 3 days of amoxicillin administration

Question 7

Distinguishing features of Acute graft vs. host

Answer 7

2-4 weeks post transplant, may be pruritic

Question 8

Distinguishing features of HIV

Answer 8

acute onset 1-6 weeks post infection (involves face, palms, and soles). Systemic sx with LAD +/- oral and genital aphthous like ulcers

Question 9

Measles infectious timeframe

Answer 9

Disease can be spread 4 days before prodrome starts until 4 days after rash starts. Incubation period before prodrome is 10-12 days

Question 10

Koplick spots

Answer 10

Blue-white spots with red halo, usually appear 1-2 days before exanthem

Question 11

Eruptive phase of measles

Answer 11

Initial macules and papules are blanchable

Question 12

Tx of measles

Answer 12

Supportive but can give Vitamin A

Question 13

Hand, Foot, and mouth presentation

Answer 13

Oral lesions are usually initial sign with aphthae like erosions. Exanthem appears one day after enanthem with vesicular palmoplantar eruption (cloudy vesicles with red halo)

Question 14

DDx of hand foot and mouth oral lesions

Answer 14

Herpes stomatitis

Question 15

Clinical presentation of Scarlet fever

Answer 15

Sudden onset fever + pharyngitis, oral cavity red with white strawberry tongue. Rash begins on neck and face (sandpaper) with circumoral pallor and spares palms and soles. Pastia signs (linear petechiae) are found in skin folds and white strawberry tongue turns to red. Prominent desquamation as rash resolves along with transverse groove in nails (Beau’s lines)

Question 16

Etiology of scarlet fever

Answer 16

Streptococcal pyrogenic exotoxin A

Question 17

Tx of scarlet fever

Answer 17

Penicillin

Question 18

Eruptive phase of rubella

Answer 18

Begins of neck/face and within hours spreads to trunk and extremities. Less vivid color than scarlet fever and lacks the blue/violaceous hue of measles. Can see associated polyarthritis

Question 19

Colloquial name for rubella

Answer 19

German measles/3-day measles

Question 20

Erythema Infectiosum etiology

Answer 20

Parvo B19 which targets the red cell receptor globoside (P antigen) of the erythroid progenitor cells

Question 21

Eruptive phases of erythema infectiosum

Answer 21

1. Slapped cheek (can look like erysipelas) and spares the nasolabial and circumoral area
2. Net pattern erythema beginning 2 days post facial rash and spreads from extremities centrally
3. Recurrent phase: may reappear in previously affected sites over 2-3 weeks

Question 22

Arthritis in Erythema Infectiosum

Answer 22

More commonly affects adult women and can present with generalized pruritus

Question 23

DDx of Arthritis in Erythema Infectiosum

Answer 23

Acute RA, seronegative arthritis, Lyme disease, SLE

Question 24

Roseola viral etiology

Answer 24

HHV 6 and 7 (6th disease)

Question 25

Roseola clinical presentation

Answer 25

Sudden onset of high fever but otherwise surprisingly well. Rash begins as fever subsides suddenly with pale pink almond shaped macules on trunk/neck and become confluent

Question 26

Gianotti-Crosti etiology

Answer 26

EBV is often cause, see 1-10mm pruritic papules/papulovesicles commonly limited to extremities and face

Question 27

Three phases of Kawasaki dz

Answer 27

1. Acute: febrile phase w/ non-exudative conjuncitivitis, mouth/lip changes, swelling and redness of hands and feet, rash, and cervical LAD
2. Subacute: end of fever, desquamation of fingers and toes, arthritis
3. Convalescent: Clinical signs disappear and ESR beging to normalize

Question 28

DDx of Kawasaki

Answer 28

Viral infections, scarlet fever, SSSS, Toxic shock, drug hypersensitivity, SJS, juvenille RA, RMSF, Leptospirosis, mercury hypersensitivity