Neutrophilic panniculitis: algorithmic approach to a heterogeneous group of disorders.

CONTEXT: Neutrophilic panniculitis encompasses an etiologically and morphologically heterogeneous group of disorders. Correct histopathologic diagnosis is important in identifying certain systemic diseases and guiding appropriate treatment. OBJECTIVE: To review the clinical and histopathologic features of different types of neutrophilic panniculitis, and to provide a diagnostic algorithm for these disorders. DATA SOURCES: A review of the literature with emphasis on the distinguishing features of different entities was performed. CONCLUSIONS: Evaluation for neutrophilic panniculitis entails paying close attention to the pattern of inflammation, the type of fat necrosis present, any evidence of vascular damage, and other relevant histopathologic features. An algorithmic approach integrating all histopathologic, clinical, and laboratory findings is required for correct diagnosis.

Application of the QuantiFERON®-TB Gold test in erythema induratum.

Erythema induratum (EI) was originally described by Ernest Bazin in 1861 as nodular lesions on the legs in association with tuberculosis (TB). A 33-year-old woman was referred to our hospital with tender ulcerative nodules on her legs. Skin biopsies revealed lobular inflammation of the subcutaneous fat with vasculitis. Although conservative treatment was given, the lesions did not improve. Several months later as the lesions persisted, we suspected a TB infection and additional tests were performed. The chest roentgenogram results were normal. The skin biopsies were negative for acid-fast bacilli (AFB). Mycobacterial cultures of the blood and skin were negative. However, the QuantiFERON®-TB Gold test was positive, which led to a diagnosis of latent TB infection being made. The patient was treated with multidrug antituberculosis therapy, which successfully resolved her skin lesions. Therefore, reported herein is the application of the QuantiFERON®-TB Gold test for the confirmation of latent TB infection in EI patients.

Usefulness of Interferon-γ release assays in the diagnosis of erythema induratum.

BACKGROUND: Erythema induratum (EI) manifests as tender indurated nodules on the lower legs. It may be associated with concomitant active tuberculosis (TB) and is considered a hypersensitivity reaction to mycobacterial antigens. However, the results of Mycobacterium cultures are rarely positive, and the tuberculin skin test is of limited usefulness in populations exposed to bacille Calmette-Guérin (BCG). Interferon-γ release assays (IGRAs) are alternatives to the tuberculin skin test and have high specificity. We explored the use of IGRAs as an adjunct in the diagnosis of EI. We describe 5 patients with positive tuberculin skin test results and a history of vaccination against BCG or TB in whom IGRAs supported the diagnosis of EI. OBSERVATIONS: All patients were initially seen with tender nodules on the lower legs and a history of BCG vaccination or TB. Tuberculin skin test results were positive, and chest radiographic results were normal. The results of Mycobacterium cultures were negative in all patients, and biopsy specimens were compatible with EI. Interferon-γ release assays were performed in all patients and supported initiation of anti-TB treatment in 4 of 5 patients. Conclusion  Interferon-γ release assays may have value as an adjunct in the diagnosis of EI, particularly in the setting of prior BCG exposure.

Erythema induratum of Bazin in a child: evidence for a cell-mediated hyper-response to Mycobacterium tuberculosis.

Tuberculids are chronic nodular skin eruptions believed to be a systemic reaction to Mycobacterium tuberculosis. We report on a 6-year-old boy with tender subcutaneous lesions on his legs. A tuberculin skin test resulted in 2.5 cm of induration and an interferon-gamma releasing assay was also markedly positive. A diagnosis of erythema induratum of Bazin was confirmed on skin biopsy. The patient was successfully treated with multi-drug antituberculosis therapy.

Erythema induratum of Bazin. Evidence of T-lymphocyte hyperresponsiveness to purified protein derivative of tuberculin: report of two cases and treatment.

BACKGROUND AND DESIGN: Erythema induratum of Bazin, a chronic form of nodular vasculitis, may be associated with chronic infections by Mycobacterium tuberculosis. However, the true origin of the disease is a subject of speculation and remains elusive. Two female patients (58 years old and 33 years old) with a minimum 10-year history of chronic tender ulcerating nodules on the lower aspects of the legs were studied both clinically and in the response of their peripheral T cells to purified protein derivative of tuberculin. RESULTS: Both patients with no previous history of tuberculosis had strongly positive skin test results at a Mantoux 10(-4) dilution (1 unit of purified protein derivative). In response to full-course triple-agent (isoniazid, rifampicin, and ethambutol) chemotherapy, a complete remission of clinical symptoms was seen in both cases and no relapse occurred after discontinuation of therapy. A marked increase in peripheral T-lymphocyte response to purified protein derivative was found before onset of and during successful therapy. CONCLUSIONS: The present clinical observations together with the pronounced cellular response to purified protein derivative suggest a tuberculous origin of erythema induratum of Bazin.

Erythema induratum of Bazin as a type of tuberculid.

We report three cases of patients with erythema induratum of Bazin who showed extreme tuberculin hypersensitivity reactions and a good therapeutic response to isoniazid. In the first patient satellite lesions with epithelioid granuloma formation developed 3 weeks after injection of purified protein derivative. In the second patient a high fever developed 1 day after injection of purified protein derivative, and the third patient blistered at the injection site; the histopathologic pattern was similar to erythema multiforme. Immunohistologic study of the epithelioid granulomas demonstrated a predominance of Leu-1--bearing, Leu-3a--bearing, and human lymphocyte antigen-DR-expressing cells. We conclude that erythema induratum of Bazin represents a tuberculid caused by heightened delayed-type hypersensitivity to components of tubercle bacilli released from latent foci of infection.

S-100-protein-positive dendritic cells in nodular vasculitis.

We investigated the distribution of S-100-protein-positive dendritic cells in 20 cases of nodular vasculitis (erythema induratum Bazin). The cells were identified by immunohistochemical demonstration in paraffin sections. S-100-protein-positive dendritic cells were present in all cases and comprised up to 11% of the infiltrating cells in lymphohistiocytic areas (mean 3.7%). Because of the dendritic shape and the association with lymphocytes the cells are considered to represent T-zone histiocytes. Our findings suggest a possible role of delayed-type hypersensitivity in nodular vasculitis.

Nodules on the legs. A clinical, histological and immunohistological study of 82 patients representing different types of nodular panniculitis.

Eighty-two cases of nodular panniculitis of the legs were examined clinically, histologically and immunohistologically. Clinically the cases could be divided into four groups: typical erythema nodosum (ENty) (35 cases), erythema nodosum migrans (ENmi) (11 cases), erythema induratum (EI) (11 cases) and the remaining 25 cases not consistent with the others as "non-definite panniculitis" (NDP). The main histological categories were septal panniculitis and lobular panniculitis, the former including erythema nodosum, both typical and migrans, the latter EI and NDP. Lobular panniculitis was divided into three subgroups in which the most prominent histological features were epithelioid cell granuloma, vasculitis and palissading granuloma, respectively. Immunoglobulins in the vessel walls were found in 5 of the 46 cases of erythema nodosum, in 19 of the 36 EI and NDP cases and, in the histological groups in 4 of the 43 cases of septal panniculitis and in 19 of the 35 cases of lobular panniculitis, respectively. Fibrin was found in the walls of the papillary capillaries and deep dermal vessels in the majority of cases of lobular panniculitis. In EI and NDP the follow-up time was 40 months, on average. Twenty-two patients were treated with antituberculous drugs, 15 became symptomless, as did 5 of the 12 patients who were not treated at all.