0071643192.pdf

DERMATOLOGY

ERYTHEMA NODOSUM

SYMPTOMS/EXAM

■ Inflammatory reaction of the subcutaneous fat causing numerous, tender, ery-

thematous nodules most commonly on the pretibial area of the lower extremi-

ties; lesions may turn yellow-purple and resemble bruises (see Figure 17.4)

■ Most common in young women, with female-to-male ratio of 4:1

■ Ulceration is not a typical feature and may suggest an alternative diagnosis.

TREATMENT

■ Symptomatic treatment includes bed rest, leg elevation, and NSAIDs.

■ Additional treatment depends on underlying cause.

PITYRIASIS ROSEA

SYMPTOMS/EXAM

■ Pruritic, but otherwise a benign self-limited illness

■ Multiple 1- to 2-cm-diameter, salmon-colored oval plaques following the

ribs in a “Christmas tree” pattern on the trunk

■ In half of cases, a larger solitary lesion called a “herald patch” precedes the

other lesions by 7 days.

ETIOLOGY

■ Unknown

FIGURE 17.4. Erythema nodosum.

(Reproduced, with permission, from Tintinalli JE, Kelen GD, Stapczynski JS. Emergency

Medicine: A Comprehensive Study Guide, 6th ed. New York: McGraw-Hill, 2004:1531.)

Causes of Erythema

NODOSUM:

NOknown cause: Even

after a thorough

evaluation, the cause

of EN remains

unknown in 40–60%

of cases.

Drugs (OCP,

sulfonamides, PCN,

vaccines)

Other

(Coccidiodomycosis,

TB, Herpes, EBV,

pregnancy)

Strep (most

common)/Sarcoidosis

Ulcerative

colitis/inflammatory

bowel disease

Malignancy (leukemia,

lymphoma)