Causes of Vasculitic Rash

Vasculitic rash can be present in the form of an acute, subacute, or chronic rash.  The rash almost always is found on the lower limbs.  Purpura, bleeding under the skin, and small spots of bleeding, called petechiae, may be present in acute vasculitis.  There may also be large bruises and in some cases blood flow to the skin in impaired and the skin turns black and ulcerates, called necrosis.  Fever and joint pains can also exist during acute vasculitis.  An acute attack usually lasts about two to three weeks.  A vasculitic rash that is subacute is milder than the acute form.  Some people have chronic vasculitis.  Patients with this form of rash tend to feel well, but have the rashes and bruising for several months at a time.

There are many different causes of vasculitic rash, all of which cause the same inflammatory response in the wall of the blood vessel.  The blood vessel wall can sustain a direct injury from bacteria or viruses.  Indirect injuries which cause inflammation of the blood vessel wall can be caused by the activation of antibodies or certain groups of proteins that also attack infections.

Since the response to infection can cause this rash, then treatment of the underlying infection is a common treatment for the rash.  The infection could be viral or bacterial, but hepatitis B and C are more common causes.  Some people’s systems respond to certain medications in a way that can cause the rash.  The medications that most commonly cause vasculitis are thiazide diuretics, anticoagulants, antibiotics, and non-steroidal anti inflammatory drugs.  Vasculitis is more likely to develop when the flow of blood is reduced or restricted.  Reduced blood flow could be caused by the use of beta blocker, the presence of varicose veins, and cold weather, among other things.

Vasculitis is a common complication of autoimmune disorders such as system lupus, rheumatoid arthritis, and polyarteritis nodosa.  Autoimmune disorders are ones where the patient’s antibodies target the person’s own tissue.  When the antibodies attack blood vessel walls, vasculitis occurs.

Sometimes vasculitis can be diagnosed solely based on the appearance of the rash, but sometimes further testing in needed for a correct diagnosis.  A skin biopsy can prove that the rash is vasculitis, but the cause of the vasculitis needs to be known in order to treat it.  Blood tests may be ordered to look for liver and kidney disease and urine tests can detect protein or bleeding.  Tests that could point to lupus or other autoimmune diseases may be ordered.  Blood tests can also be used to look for hepatitis B and C.  Sometimes this extensive testing is not performed unless there is a recurrence of vasculitis since, for most patients, no underlying disease or cause is ever found.

Unless an underlying cause of the vasculitic rash is known, most treatment measures focus on relieving the unpleasant symptoms that come with the rash.  It has been found to be helpful to rest and elevate the limb.  Pain relievers may also help, however if you use a non-steroidal anti inflammatory drug and the rash worsens, remember that NSAIDS can be the cause of vasculitis.

If the cause of the rash is known, treatment of the underlying condition will usually cause the rash to heal.  For example, if an infection is causing the vasculitis, then treating the infection should resolve the rash.  If the vasculitis is persistent or caused by a chronic condition such as lupus, then medications may be needed to control the rash.  Prednisone, anti-inflammatory drugs, and colchicines may be used to treat the rash while the underlying disease is brought under control.

If you’ve experienced vasculitis, it may take several weeks or even months to fully heal and it may return throughout your life.  If the vasculitis was caused by an underlying chronic disease, or if it affected vital organs, further treatment and prevention may be necessary.