CASE REPORT Induratum Report of a Rare Entity Bao Anh Patrick Tran, Tiffany Alexander, Wen Chen, Mary Maiberger

ABSTRACT: is a rare granulomatous test for . On physical examination, multiple deep lobular that most commonly affects women subcutaneous nodules were scattered on the bilateral lower in their 40s. The term ‘‘erythema induratum of Bazin’’ extremities. There was a hyperpigmented patch overlying a refers to the tuberculosis-associated lesions, and ‘‘ery- crop of nodules on the left calf (Figure 1). An interferon thema induratum of Whitfield’’ refers to lesions that are gamma release assay was positive, and chest x-ray was nontuberculous. It presents as tender erythematous normal, consistent with latent tuberculosis. A punch subcutaneous nodules on the lower extremities. Other of a nodule on the left hip was performed, which revealed a conditions such as should be ruled diffuse septolobular panniculitis (Figure 2 and Figure 3). out. Histologically, erythema induratum is described as The infiltrate consisted of lymphocytes, macrophages, and a lobular panniculitis and may include . There poorly formed granulomas. Septal fibrosis was seen. In ad- have been few reported cases in the United States. In dition, there was vasculitis involving the small venules. Given this case report, we will discuss the clinical features, the clinical and histopathologic findings, he was diagnosed histopathology, differential diagnosis, and management with erythema induratum. He was initiated on a 9-month of erythema induratum. course of isoniazid and had resolution of the lower ex- Key words: Erythema Induratum, Lobular, Lower Extremity tremity nodules after 5 months of treatment. Nodules, Panniculitis, Tuberculosis DISCUSSION CASE REPORT Erythema induratum is synonymous with nodular vascu- An African American man in his 70s presented with more litis. When of tuberculous etiology, it has been called than a 20-year history of firm nodules on the left calf. Bazin’s disease or erythema induratum of Bazin; in non- In addition, he reported a 6-month history of new-onset tuberculous cases, it is referred to as erythema induratum of tender nodules on the posterior lower extremities and Whitfield (Whitfield, 1901). The disease was first described thighs. He denied systemic symptoms such as , chills, by Bazin in 1861 as subcutaneous, indurated, erythematous or pulmonary or gastrointestinal symptoms. His past medi- nodules on the posterior lower legs of women (Bazin, 1861). cal history was significant for , treated breast , and an untreated positive purified protein derivative

Bao Anh Patrick Tran, MD, Department of , Howard University Hospital, Washington, DC. Tiffany Alexander, BA, Howard University College of Medicine, Washington, DC. Wen Chen, MD, Department of Pathology, Washington DC Veterans Affairs Medical Center, Washington, DC. Mary Maiberger, MD, Department of Dermatology, Washington DC Veterans Affairs Medical Center, Washington, DC. The authors declare no conflict of interest. Correspondence concerning this article should be addressed to Bao Anh Patrick Tran, MD, Department of Dermatology, Howard University Hospital, 2041 Georgia Ave, NW #2107, Washington, DC 20060. E-mail: [email protected] Copyright B 2017 by the Dermatology Nurses’ Association. FIGURE 1. Hyperpigmented patch on the left calf overlying DOI: 10.1097/JDN.0000000000000298 a group of subcutaneous nodules.

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Copyright © 2017 Dermatology Nurses' Association. Unauthorized reproduction of this article is prohibited. ease, positive purified protein derivative test, or positive interferon gamma release assay (Bolognia et al., 2012). The histopathology has classically been described as a mostly lobular panniculitis but can reveal a mixed septal and lobular panniculitis as well (Requena & Yus, 2001). The inflammatory infiltrate may include neutrophils, lym- phocytes, macrophages, and giant cells (Baselga, 1997). There can be a component of a caseous or coagulative necrosis (Requena & Yus, 2001). Vasculitis is usually seen, but its inclusion as a diagnostic criteria of erythema induratum is contentious (Schneider et al., 1995). The nature of the vessel involved varies from large septal arteries and veins to small venules of the fat lobules (Segura, Pujol, & Trinidade, 2008) (Figure 4). The differential diagnosis includes erythema nodosum, although the nodules tend to be on the anterior lower legs FIGURE 2. Deep-seated subcutaneous tender nodule on and resolve sooner. Other entities in the differential include the left hip. tertiary syphilis (syphilitic gumma), polyarteritis nodosa, and other infectious and inflammatory panniculitis. Histo- Epidemiologically, erythema induratum is an extremely logically, pernio may appear similar to erythema induratum rare diagnosis. The disease has a female predominance but can usually be ruled out based on clinical history of up to 90% (Bolognia, Jorizzo, & Schaffer, 2012). There (Requena & Yus, 2001). is no racial predilection. Affected patients are usually Treatment is directed at the underlying cause, such as middle aged with a mean in the fourth decade of life, isoniazid for cases associated with tuberculosis. Other ther- although the range is wide, and pediatric cases have been apies used for the nodules include corticosteroids, nonsteroi- reported. Erythema induratum of Bazin is more common dal anti-inflammatory drugs, potassium iodide, tetracycline, in populations where tuberculosis is endemic (Bolognia gold, and mycophenolate mofetil. Supportive measures in- et al., 2012). clude rest, compression stockings, and smoking cessation. The lesions are usually painful but may be tender only We present this case of erythema induratum as a rarely on palpation or may be asymptomatic. Although they most reported entity, given the low incidence of tuberculosis in often present on the lower legs, they have also been reported the United States. Furthermore, this patient showed some on the feet, thighs, buttocks, and even arms (Baselga, 1997). less common features in that the patient is male, although The clinical course may be prolonged; nodules may ulcerate, the disease is predominantly seen in women, and the heal with scarring, and recur (Requena & Yus, 2001). In histology revealed a septolobular panniculitis rather than cases associated with tuberculosis, there may be signs of a mainly lobular one. Erythema induratum remains an pulmonary , radiographic evidence of active dis- important consideration in the differential diagnosis of lower extremity nodules. h

FIGURE 3. Hematoxylin and Eosin stain, original magnifica- tion of 100. Microscopic examination revealed a diffuse, septolobular panniculitis. The infiltrate was lymphocytic FIGURE 4. Hematoxylin and Eosin stain, original magnification with poorly formed granulomas. of 100. Vasculitis involving the small venules of fat lobules.

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Copyright © 2017 Dermatology Nurses' Association. Unauthorized reproduction of this article is prohibited. REFERENCES Schneider, J. W., Jordan, H. F., Geiger, D. H., Victor, T., Van Helden, P. D., Baselga, E. (1997). Detection of Mycobacterium tuberculosis DNA in lobular & Rossouw, D. J. (1995). Erythema induratum of Bazin: A clinicopath- granulomatous panniculitis (erythema induratum-). Archives ologic study of 20 cases and detection of Mycobacterium tuberculosis of Dermatology, 133(4), 457Y462. doi:10.1001/archderm.1997.03890400057008 DNA in skin lesions by polymerase chain reaction. American Journal of Dermatopathology, 17,350Y356. Bazin, E. (1861). Lec¸ons the´oriques et cliniques sur la scrofule: Conside´re´e en ellem4me et dans ses rapports avec la syphilis, la dartre et l’arthritis Segura, S. S., Pujol, R. M., & Trinidade, F. (2008). Vasculitis in erythema (2nd ed.). Paris, France: Adrien Delahaye. induratum of Bazin: A histopathologic study of 101 biopsy specimens from 86 patients. Journal of the American Academy of Dermatology, 59, Bolognia, J., Jorizzo, J. L., & Schaffer, J. V. (2012). Dermatology (3rd ed., Y Vol. 2). Philadelphia, PA: Elsevier/Saunders. 839 851. Requena, L., & Yus, E. S. (2001). Panniculitis: Part II. Mostly lobular Whitfield, A. (1901). On the nature of the disease known as erythema panniculitis. Journal of the American Academy of Dermatology, induratum scrofulosorum. The American Journal of the Medical Sciences, 45(3), 325Y364. doi:10.1067/mjd.2001.114735 122,828Y834.

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