Introduction

Leukocytoclastic vasculitis is a small-vessel vasculitis and often involves systemic organs other than the skin, such as the joints, gastrointestinal tract, and kidney [1]. If it is confined to the dermal postcapillary venules, then it is designated as cutaneous leukocytoclastic vasculitis (CLV) [2]. The histopathology is characterized by fibrinoid necrosis of the vessel walls, extravasation of red blood cells, and the perivascular presence of polymorphonuclear leukocytes with fragmented nuclei [3]. In addition to the skin lesions, major clinical manifestations include palpable purpura and petechiae, fever, malaise, myalgias, and arthralgias [4]. There are many identifiable etiologic factors of CLV including: drugs, infection, collagen vascular disease, and malignancy [1, 5]. Among the infectious agents, bacteria and viruses are well recognized as causes of CLV, but Mycobacterium tuberculosis is rarely reported to be associated with CLV. In instances where M. tuberculosis is determined to be the cause, the exact pathogenesis of CLV due to M. tuberculosis remains unknown. Here, we report a case of tuberculous lymphadenitis presenting with CLV and a review of the literature.

Case report

A 49-year-old Korean man was admitted to our hospital presenting with a 1 week history of fever, myalgia, and arthralgia. He indicated a sensation of warmth and tenderness on the right side of his neck. He had no personal or family history of medical illness and had not taken any medications recently. Upon physical examination, his body temperature was 39.5°C, several lymph nodes were palpable on his right neck, and one small round purpura was discovered on his anterior lower right leg. On day 3 of his admission, multiple palpable purpura appeared on both lower legs and progressively spread to both thighs (Fig. 1). Computerized tomography (CT) of his neck suggested probable cervical tuberculous lymphadenopathy. A biopsy of the cervical lymph nodes was performed, and the histology revealed chronic granulomatous inflammation with caseous necrosis (Fig. 2). Acid-fast bacilli were not found on Ziehl-Nielsen staining, but polymerase chain reaction (PCR) for Mycobacterium tuberculosis was positive. The histology of the biopsy from the purpura on the skin revealed leukocytoclastic vasculitis without granuloma (Fig. 3). Initial laboratory findings were as follows: WBC: 3,500/mm3 (neutrophil 84.4%, lymphocyte 11%, eosinophil 1%), Hb: 10.8 g/dl, platelets: 121,000/mm3, erythrocyte sedimentation rate: 42 mm/h, C-reactive protein: 25.1 mg/dl, AST/ALT: 81/27 IU/L, and BUN/Cr: 5.1/0.9 mg/dl. Serological markers for HIV, cytomegalovirus, Epstein-Barr virus, Herpes simplex virus, Varicella-zoster virus, Hanta virus, leptospirosis, tsutsugamushi, hepatitis B and C, mycoplasma, and syphilis were all negative. Antinuclear antibody, anti-dsDNA antibody, anti-Ro antibody, anti-La antibody, and antineutrophil cytoplasmic antibody (ANCA) were also negative. Complement level was normal. Levels of serum IgG/A/M were 1,700/415/103 mg/dl, respectively (reference values: 700–1,600 mg/dl, 70–400 mg/dl, and 40–230 mg/dl, respectively). Urinalysis was within the normal range. The tuberculin test (2 TU) was positive (7 × 6 mm2). Cultures of blood, stool, and urine were negative. Radiologic studies were performed to detect any underlying disease or evidence of vasculitis within the internal organs. The CT scans of the chest, abdomen and pelvis revealed no abnormalities. The angiography of the celiac artery, superior mesenteric artery, and both renal arteries revealed no stenosis or aneurysmal changes due to vasculitis. The patient received standard anti-tuberculosis therapy with isoniazid, rifampicin, ethambutol, and pyrazinamide. Over the next week his symptoms subsided, and the purpura on his legs gradually disappeared. During the 6-month course of treatment, there was no recurrence of purpura on the skin.

Fig. 1
figure 1

Multiple palpable purpura were observed on both lower extremities

Full size image
Fig. 2
figure 2

Biopsy of a lymph node in the right neck shows chronic granulomatous inflammation with caseous necrosis

Full size image
Fig. 3
figure 3

Biopsy of a skin lesion shows vascular damage with perivascular neutrophilic infiltrate, eosinophilic fibrinoid changes in vessel walls, and nuclear debris, which is comparable to pathology seen in leukocytoclastic vasculitis

Full size image

Discussion

The CLV is identical to dermal lesions that occur as a component of systemic small-vessel vasculitis [2]. Twenty percent of leukocytoclastic vasculitis cases involve a systemic organ [4]. The exact pathogenesis of CLV remains uncertain, but it appears to be mediated by the deposition of circulating immune complexes within specific vessels. The deposits subsequently activate the complement cascade and release vasoactive substances and chemotactic factors that cause the accumulation of polymorphonuclear cells and release of lysosomal enzymes [6, 7], which leads to vessel wall injury. However, other autoantibodies such as ANCA, inflammatory mediators, and adhesion molecules may be involved in the pathogenesis of CLV. In addition, various conditions and diseases can cause CLV; drugs and infection cause approximately 10% of vasculitic skin lesions [1]. Malignancy is associated with less than 1% of cases of CLV [8]. According to previous studies, up to 61% of cases of CLV are idiopathic, depending on the degree of investigation and the duration of follow up [1].

Various infectious agents, such as bacteria, viruses, fungi, protozoa and helminthes, are associated with vasculitis. However, M. tuberculosis is rarely reported to be associated with CLV, and we found only 8 cases reported in the English literature (Table 1). Four patients (50%) had pulmonary tuberculosis, and three patients (37.5%) had tuberculous lymphadenitis. Acid-fast bacilli were found within sputum in four patients, and within tissue from lymph nodes in three patients. Lee et al. used PCR with blood mononuclear cells in order to diagnose tuberculosis, although this is not a standard test [13]. Four patients (50%) presented with purpura on the skin prior to their diagnosis of tuberculosis. The purpura in all eight patients subsided completely after anti-tuberculosis treatment, and did not recur.

Table 1 Cases of cutaneous leukocytoclastic vasculitis (CLV) associated with Mycobacterium tuberculosis
Full size table

Tuberculosis can manifest itself in two types of skin lesions: direct lesions and hypersensitivity vasculitis [15]. The major difference between these lesions is whether or not mycobacteria exist within the lesion. Hypersensitivity vasculitis can be caused by the deposition of immune complexes formed by antibodies against M. tuberculosis proteins in the small-vessel walls, and therefore the organism is absent in the lesion [15]. The existence of circulating immune complexes has been demonstrated in 56% of patients with active tuberculosis, and it has been suggested that the sequential measurement of these complexes could be useful as a guide to successful treatment of tuberculosis [16]. However, not all immune complexes in tuberculosis cause vasculitis, and the prevalence of vasculitis in tuberculosis seems to be very low. In a study by Visser and Heyl [11], there was only one CLV case among 92 patients with cutaneous tuberculosis.

In conclusion, although incidence is rare, tuberculosis should be considered as a possible cause of CLV. In all previous cases of CLV with tuberculosis, anti-tuberculosis treatment completely resolved the skin lesions.