What is nodular vasculitis?
Nodular vasculitis refers to a group of poorly defined conditions causing nodules on the legs, in which inflamed blood vessels (vasculitis) are found on biopsy.
Nodular vasculitis mainly affects women aged 30 to 60. Men are less often affected. The nodules or lumps are usually found on the backs of the lower legs but they may also occur on the thighs and arms. One or both legs may be involved. Lesions range in size from small bumps to large plaques. They may be more easily seen than felt.
Other features include:
- Aching legs
- Red-purple discolouration
- Cool skin
- Varicose veins.
Evolution of the nodules is usually slow although in some there can be acute inflammation or ulceration. Ulcers usually persist for several weeks then heal. Most nodules heal slowly with little atrophy or scarring. If superficial, they give the impression of being tethered to the skin and may leave a depression that takes several months to fill.
Nodules may continue to erupt at irregular intervals over months or years.
What is the cause of nodular vasculitis?
Nodular vasculitis is a type of panniculitis. The exact cause is unknown but the patchy inflammation in the blood vessels and lymphatics in the deep dermis and subcutaneous fat appears to relate to a slowed circulation. Factors contributing to this include:
- Cold, fat legs
- Venous disease
- Hypertension (high blood pressure).
Slowing of the flow in the deep vessels can also encourage deposition of bacteria from the blood stream, including tubercle bacilli, and in some patients nodular vasculitis is a sign of tuberculosis, when it may be called erythema induratum or Bazin disease.
Skin biopsy of the nodules reveals panniculitis, with varying degrees of inflammation of the blood vessels and lymphatics in the deep dermis and subcutaneous tissue.
There are no laboratory findings which are consistently abnormal in nodular vasculitis. Occult tuberculosis should be excluded.
Other causes of nodules on the legs
Nodular lesions of the legs with a vascular basis include:
- Nodular erythrocyanosis
- Erythema nodosum
- Subacute nodular migratory panniculitis
- Livedo with nodules
- Polyarteritis nodosa.
There is no specific treatment for nodular vasculitis, but the following measures may be helpful.
- Supportive bandages and compression hosiery
- Weight loss
- Elevation of the legs
- Keeping warm
Medications that have been reported to be helpful include:
- Antibiotics – prolonged antituberculous therapy has been successful in cases presumed to be tuberculous.
- Anti-inflammatory drugs
- Short-term systemic corticosteroids
- Fibrinolytic therapy
- Potassium iodide