Synonyms: Bazin's disease, nodular vasculitis, tuberculous erythema induratum, tuberculosum, tuberculosis cutis indurativa and nodose tuberculid

Erythema induratum is a rare condition that classically produces painful, firm and sometimes ulcerated nodules on the lower legs in association with tuberculosis (TB).

Classification

In 1945 the term nodular vasculitis was coined to describe chronic inflammatory nodules of the legs that showed histopathological changes similar to those of erythema induratum, but without an association with TB. The vasculitis is of the larger vessels with panniculitis - an inflammation involving subcutaneous fat and occasionally muscle, with or without vasculitis.¹

Erythema induratum and nodular vasculitis had been seen as the same disease for many years but nodular vasculitis is now considered to be a multifactorial syndrome of lobular panniculitis in which tuberculosis may or may not be one of the various aetiologies.

It is now classified as:

• Erythema induratum of Bazin type - associated with TB.
• Erythema induratum (or nodular vasculitis) of Whitfield type - no association with TB.

Pathophysiology

The disease or diseases represent an inflammatory reaction. One antigen is Mycobacterium tuberculosis. Patients with erythema induratum have a strongly positive tuberculin skin test and a marked increase in their peripheral T-lymphocyte response to purified protein derivative (PPD) of tuberculin, which is a delayed (type IV) hypersensitivity reaction.
In cases of erythema induratum with a negative tuberculin test, the cause is unknown but the possibility of hepatitis C being implicated has been suggested.²

Epidemiology

• The disease is still seen in countries where tuberculosis is rife but it is rarely seen in western societies. When it is, the type is more often Whitfield than Bazin. Erythema induratum is still prevalent in India, Hong Kong, and South Africa.
• There is a marked female preponderance.
• The most common presentation is in a young woman in her 20s but it may present at a later age.

Presentation

• The usual site of the lesions is the lower legs: in the calves, with the shins involved less often; however, it may occur in other places too. The trunk, buttocks, thighs, and arms can be involved but this is much rarer. The nodules are usually grouped on the lower third of the legs, especially around the ankles.³
• The nodules are tender and erythematous.
• The nodules may ulcerate with bluish borders, and cold weather may be the precipitating factor. This produces irregular, shallow ulcers that may cause permanent scarring with hyperpigmentation of the lesions.They may run a chronic and recurrent course.
• The legs may be oedematous.
• About half of patients will give a past or present history of tuberculosis. This is most often pulmonary tuberculosis with cervical lymphadenopathy second.

Differential diagnosis

• Cold panniculitis.
• Chilblain.
• Lymphoma.
• Erythema nodosum leprosum.
• Dermatitis artefacta.
• Alpha-1-antitrypsin deficiency panniculitis.
• Lupus panniculitis.

Investigations

• FBC and erythrocyte sedimentation rate (ESR).
• CXR.
• If a Mantoux' test is performed it should be at a 1:10,000 dilution as the response can be very marked. Unlike nodular vasculitis, erythema induratum is seen as a tuberculous disease and a strongly positive Mantoux' response is regarded as an important diagnostic feature.
• A lesion may be biopsied and polymerase chain reaction (PCR) provides rapid and sensitive detection of M. tuberculosis in a formalin-fixed, paraffin-embedded specimen. This can differentiate tuberculous disease from other aetiologies.⁴ A study from Spain used PCR amplification on skin biopsy specimens and found positive for M. tuberculosis in 77%. There was no correlation with clinical findings.⁵
• An excision biopsy is usually recommended, going down to an adequate level of subcutaneous fat. Stains for bacteria and fungi may be used and an attempt to culture the tubercle baccillus and other organisms. Histological features are characteristic.⁶ Specimens for culture must be sent to the laboratory without delay and they must not be placed in formalin.

Associated diseases

• The most important associated disease is TB, old or active. Erythema induratum of Bazin and renal TB can be associated.⁷
• A variation of erythema induratum (nodular tuberculid) with a granulomatous vasculitis occurring at the dermohypodermal junction has been reported in 5 patients with HIV disease.⁸
• Episcleritis in children has also been reported.⁹

Management

• See separate article Tuberculosis Management which deals with TB treatment.
• Bedrest may be indicated.
• Steroids should be used with caution in old or active tuberculosis.

Complications

If not properly treated, the lesions can be persistent, ulcerated and cause scarring.

Prognosis

If TB is the cause, the lesions will disappear with appropriate TB treatment.

Historical notes

Pierre-Antoine-Ernest Bazin was born in 1807 and died in 1878. He described erythema induratum in 1861.

Document references

1. Scheinfeld NS; Erythema induratum (Nodular Vasculitis), eMedicine, Jan 2010
2. Gimenez-Garcia R, Sanchez-Ramon S, Sanchez-Antolin G, et al; Red fingers syndrome and recurrent panniculitis in a patient with chronic hepatitis C. J Eur Acad Dermatol Venereol. 2003 Nov;17(6):692-4. [abstract]
3. Gilchrist H, Patterson JW; Erythema nodosum and erythema induratum (nodular vasculitis): diagnosis and Dermatol Ther. 2010 Jul-Aug;23(4):320-7. [abstract]
4. Sharon V, Goodarzi H, Chambers CJ, et al; Erythema induratum of Bazin. Dermatol Online J. 2010 Apr 15;16(4):1. [abstract]
5. Baselga E, Margall N, Barnadas MA, et al; Detection of Mycobacterium tuberculosis DNA in lobular granulomatous panniculitis (erythema induratum-nodular vasculitis). Arch Dermatol. 1997 Apr;133(4):457-62. [abstract]
6. Leow LJ, Pintens S, Pigott PC, et al; Erythema induratum - a hypersensitivity reaction to Mycobacterium tuberculosis. Aust Fam Physician. 2006 Jul;35(7):521-2. [abstract]
7. Daher Ede F, Silva Junior GB, Pinheiro HC, et al; Erythema induratum of Bazin and renal tuberculosis: report of an association. Rev Inst Med Trop Sao Paulo. 2004 Sep-Oct;46(5):295-8. Epub 2004 Oct 22. [abstract]
8. Friedman PC, Husain S, Grossman ME; Nodular tuberculid in a patient with HIV. J Am Acad Dermatol. 2005 Aug;53(2 Suppl 1):S154-6. [abstract]
9. Leahy TR, Downey P, Ramsay B, et al; Erythema induratum of Bazin and episcleritis in a 6 year old girl. Arch Dis Child. 2005 Nov;90(11):1132.

Acknowledgements