Case: A pre-teen girl, living in central California, recently started on fluconazole, now presenting with a bilateral leg rash. What is your diagnosis? Click on the image for a larger view.

Poll Results

[plot id=”1″]

[su_spoiler title=”Diagnosis” style=”fancy” icon=”chevron-circle”]

Erythema nodosum, secondary to coccidioidomycosis

Explanation

Erythema nodosum is a cutaneous reaction consisting of inflammatory, tender erythematous subcutaneous nodular lesions. The classically painful rash is located on the lower extremities and usually regresses spontaneously. It is associated with a wide variety of disease processes^1,2 including:

• Most common cause: Streptococcal infections
• Other causes:
  • Behcet’s syndrome
  • Oral contraceptive use
  • Pregnancy
  • Sarcoidosis
  • Tuberculosis
  • Viral infections

Coccidioidomycosis is endemic to certain arid parts of the Southwest United States. Erythema nodosum is the most characteristic reactive cutaneous manifestation of coccidioidomycosis. It presents 1-3 weeks after onset of illness and is usually self-limited.³ While strep infections are the most common cause of erythema nodosum, in a patient who has recently visited the American southwest, suspect coccidioidomycosis.

[/su_spoiler]

Master Clinician Bedside Pearls

Stuart Swadron, MD – Professor of Emergency Medicine, Keck School of Medicine of the University of Southern California (provided to ALiEM and recorded by Swadron, 2014)

Author information

The post Diagnose on Sight: Bilateral Leg Rash appeared first on ALiEM.