Unilateral erythaema nodosum: atypical presentation in paediatrics

Description

A previously healthy 12-year-old boy was observed in the emergency department due to pain and erythaema in the left shin for the past 2 weeks. He was discharged with flucloxacilin for cellulitis. One week later, he returned with oedema and erythaema of the left shin, with palpable nodules and purple discolouration (figure 1). The right leg was normal. Oropharyngeal hyperaemia was observed.

Figure 1

Erythaema, oedema and nodules in the left shin.

Complementary study revealed  erythrocyte sedimentation rate of 12 mm/hour and antistreptolysin O titre was 985 UI/mL (normal range 0–408 UI/mL). C reactive protein was <2.90 mg/dL; autoimmunity study, infectious serologies (hepatitis B virus and Epstein-Barr virus, EBV, Mycoplasma pneumoniae and Salmonella spp.) rapid strep test and Mantoux test were negative. Ultrasound showed subcutaneous oedema. Biopsy revealed septal panniculitis, compatible with erythaema nodosum (figure 2). He was discharged.

Figure 2

Incisional biopsy....

http://ift.tt/2zeVX9t