Erythema induratum of Bazin

Here we present the case of a 70-year-old female born in Rio de Janeiro with a histopathological clinical diagnosis made September, 2018, of non-endemic pemphigus foliaceus. Treatment with prednisone (1mg/kg/day) with remission. In 2021, asymptomatic ulcers appeared on the patient’s right lower limb in the areas indurated due to panniculitis (Figures 1, 2). Clinical-epidemiological data of age, gender, venous insufficiency, obesity, and immunodepression supported the diagnosis of erythema induratum of Bazin (EIB).

FIGURE 1:
Ulcers with well-defined edges and surrounding erythema, covered by fibrin on the lower leg.

FIGURE 2:
Clean ulcers over indurated plaques after antibiotic therapy on the lower limb.

A fragment of ulcer biopsy in the histopathology showed a granulomatous dermohypodermitis with tissue necrosis and the presence of alcohol-acid resistant bacilli (AARB) by WADE stain and a bacilloscopy negative for AARB by Ziehl-Nielsen stain. The culture result was negative for mycobacteria; however, an ulcer swab for GenExpert detected Mycobacterium tuberculosis.

EIB affects mainly middle-aged obese women that have venous insufficiency. Recurrent, violaceous, ulcerated, and painful nodules on the calves are the cutaneous manifestations^1,2. The association with tuberculous infection has been demonstrated by polymerase chain reaction (PCR) amplification for M. tuberculosis DNA in skin biopsy specimens^1,2.

The GenExpert® MTB/RIF test is useful to distinguish tuberculosis from infections with atypical Mycobacterium. A positive result does not necessarily indicate the presence of viable organisms. In cutaneous tuberculosis, the specificity/sensitivity in the different tests are as follows: PCT GenExpert (98.4%/69%), culture (98%/23%), bacilloscopy (100%/14%)³.

Misdiagnosis of EIB in daily practice is likely, as cutaneous tuberculosis can mimick several dermatoses. EIB may need longer treatment periods, mainly in cases of recurrent episodes².

ACKNOWLEDGMENTS

No Acknowledgments.

REFERENCES

• ¹
  Azevedo TP, Oliveira ML. Analysis of cutaneous tuberculosis cases reported from 2000 to 2013 at a university hospital in Rio de Janeiro. Rev Soc Bras Med Trop. 2016;49(3):373-5.
• ²
  Mann D, Sant’Anna FM, Schmaltz CAS, Rolla V, Freitas DFS, Lyra MR, et al. Cutaneous tuberculosis in Rio de Janeiro, Brazil: description of a series of 75 cases. Int J Dermatol. 2019;58(12):1451-9.
• ³
  Menegheti GG, Tavares WD, Nassif PW, Gurgel ACM, Bersani-Amado LE, Freitas BC, et al. Polymerase chain reaction as a cutaneous tuberculosis diagnostic determinant. Rev Soc Bras Clin Méd. 2018;16(2):116-8.

• Financial Support: No financial support.

Publication Dates

• Publication in this collection
  20 Feb 2023
• Date of issue
  2023

History

• Received
  22 Sept 2022
• Accepted
  09 Dec 2022