Erythema Nodosum, Mycobacterium avium Lymphadenitis, and a 15-mm Mantoux Test

Abstract

To the Editors: We report the case of a girl with erythema nodosum (EN)1 that was triggered by a Mycobacterium avium intracellulare (MAC) cervical lymphadenitis. The association of EN with nontuberculous mycobacteria (NTM) is very rare in pediatrics.2 A 2-year-old healthy girl was admitted to our children's hospital with a 3-week illness that began with an upper respiratory infection with fever. She then developed left cervical lymphadenitis followed by erythematous maculopapular lesions in her skin, 2 weeks before admission. Outpatient amoxicillin and cefixime courses were given for presumed bacterial lymphadenitis, with no improvement. On admission, she had a solitary 5 cm indurated, warm, nonfluctuant, painful, left cervical mass and multiple erythematous and violaceous demarcated, shiny, painful raised lesions on her legs, arms, and shoulders. They erupted in patches consistent with EN. She was Canadian born and had no prior BCG vaccination, contacts with or family history of tuberculosis. Ultrasound examination confirmed extensive left-sided cervical lymphadenopathy without abscesses. Tuberculin skin test induration was 15 mm. Chest radiograph was normal and gastric aspirates were negative for M. tuberculosis. Serologic tests were negative for cytomegalovirus, Lyme disease, Epstein-Barr virus, Mycoplasma pneumoniae, and Bartonella henselae. Throat, blood, and stool cultures revealed no pathogens. Screening tests for connective tissue disorders and antistreptolysin O titer were negative. Intravenous clindamycin was administered for 6 days but the patient did not improve. Surgical drainage of the mass revealed pus that contained no organisms on Gram stain. She was discharged without antibiotics, pending culture results. Eight days later, her EN rash had resolved, but drainage was again required. Initial investigations for bacteria and fungi were negative on both specimens. The second specimen contained acid-fast bacilli. MAC was grown after 10 days of incubation from both specimens. Clarithromycin was prescribed but stopped because of oral intolerance. She required a complete excision after which rifampin was given for 6 months. No further recurrence occurred. EN is an acute panniculitis occuring more commonly in adults, associated with infectious and noninfectious etiologies.1 It presents as tender, erythematous nodules predominantly in the lower limbs, with associated symptoms including fever. It usually resolves in weeks and the etiology remains undetermined in up to half of the cases. In one of the largest EN series ever published,1 no case of NTM infection was found among 129 patients seen during 35 years. Among the infectious etiologies, Streptococcus pyogenes and tuberculosis have been the most common triggers. BCG vaccination has been occasionally implicated, and reports of pediatric EN triggered by NTM as in our patient are extremely rare in the literature.2 This case illustrates that a positive Mantoux skin test, independently of the induration size, can be seen in NTM infections.2–4 In this girl, it seems likely that a massive MAC antigen release might have contributed to the EN lesions. In children, NTM should be considered among the infectious etiologies of EN. Cervical lymphadenitis in presence of a positive Mantoux test should include suspicion of NTM infection. Presented in part as an abstract at the 41st Annual Meeting of the Infectious Diseases Society of America (IDSA)—San Diego, CA. October 9–12, 2003. Abstract No. 810.5 Heidi Budden, MD Department of Pediatrics British Columbia's Children's Hospital and The University of British Columbia Vancouver, British Columbia Canada Rolando Ulloa-Gutierrez, MD Simon Dobson, MD, FRCPC David Scheifele, MD Infectious and Immunological Diseases Division