Capillaritis

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Capillaritis is a medical condition characterized by the inflammation of the capillaries, which are the smallest blood vessels in the body. This condition often results in a distinctive rash and can be associated with various underlying causes.

Presentation

Capillaritis typically presents as a reddish-brown rash, often referred to as pigmented purpuric dermatosis. The rash is usually found on the lower legs but can appear on other parts of the body. The spots are generally small, measuring between 1-5 mm in diameter, and may coalesce into larger patches. The rash is usually asymptomatic, but some patients may experience mild itching or burning.

Causes

The exact cause of capillaritis is often unknown, but it can be associated with several factors, including:

• Medications: Certain drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and antibiotics, can trigger capillaritis.
• Infections: Viral and bacterial infections may lead to the development of capillaritis.
• Autoimmune disorders: Conditions like systemic lupus erythematosus and rheumatoid arthritis can be associated with capillaritis.
• Exercise: Intense physical activity, particularly in hot weather, can sometimes cause capillaritis.
• Idiopathic: In many cases, no specific cause is identified.

Diagnosis

Diagnosis of capillaritis is primarily clinical, based on the appearance of the rash. A skin biopsy may be performed to confirm the diagnosis and rule out other conditions. The biopsy typically shows inflammation of the capillaries with red blood cell extravasation.

Treatment

There is no specific treatment for capillaritis, and the condition often resolves on its own. Management focuses on addressing any underlying causes and alleviating symptoms. Treatment options may include:

• Discontinuation of any offending medications.
• Topical corticosteroids to reduce inflammation and itching.
• Compression stockings to improve circulation in the legs.
• Avoidance of prolonged standing or intense physical activity.

Prognosis

The prognosis for capillaritis is generally good, as the condition is usually benign and self-limiting. However, it can be chronic and recurrent in some individuals.

See also

• Vasculitis
• Purpura
• Dermatology
• Autoimmune disease