Professor Richard Watts
Consultant Rheumatologist
Honorary Professor, Norwich Medical School, University of East Anglia.
This document was updated in February 2024
What is Hypersensitivity Vasculitis?
Hypersensitivity vasculitis (HV) is a term often used to describe many different conditions. Most commonly the term is applied to a vasculitic skin rash caused by sensitivity to a drug although it may be seen in association with several other conditions. Most commonly only the skin is affected although the bowels, kidneys and joints may also be affected. . Patients with organ involvement may be diagnosed with IgA vasculitis (previously known as Henoch Schonlein Purpura).
Who are affected?
HV usually affects adults, and much less commonly children.
What are the symptoms?
The commonest symptoms are those related to the skin. Several different types of rash are recognised as HV. The commonest types of rash are small or large raised purpled spots and flat red areas. Symptoms in the skin include burning, pain or itching or the rash may not have any symptoms. Joint involvement may cause painful joints.
Bowel involvement may cause a variety of symptoms including abdominal pain and diarrhoea. Kidney involvement may lead to blood in the urine or kidney failure.
What is the aetiology (cause)?
No cause for HV is found in between one third and one half of patients. HV can be caused by a specific drug or by infection. The most common drugs include: antibiotics (particularly penicillin), non-steroidal anti-inflammatory drugs (NSAIDS) and diuretics. Infections which may be associated with HV include: hepatitis B or C virus, chronic infection with bacteria or HIV. HV type rashes and symptoms may also be seen as part of other inflammatory diseaseincluding other types of vasculitis, systemic lupus erythematosus (SLE), rheumatoid arthritis, Sjögren’s syndrome, inflammatory bowel disease and very rarely some types of cancer.
Making a diagnosis
There are no specific tests for HV. Blood tests may show evidence of inflammation. Tests are usually performed to determine if the patient has one of the diseases or infections listed in the section above. If a new drug has been recently started it may suggest that this has caused the HV. Sometimes a skin biopsy is necessary to prove that there is a vasculitis.
Treatment
If drugs are implicated as the cause then the drugs should be stopped. Where infection is the cause treatment of the infection is required. If another inflammatory disease is the cause this should be treated appropriately. Patients with skin rash and joint disease may respond to dapsone or colchicine. Some patients, particularly those with severe kidney or bowel involvement, may require treatment with steroids and other immunosuppressant drugs.
Drugs and side effects
For information on the main drugs prescribed for Hypersensitivity Vasculitis see:
For information on other drugs used in the treatment of vasculitis see Glossary of drugs and side effects.
Prognosis
For patients with HV caused by an identified drug or treatable infection the prognosis is good and the disease may not recur. For patients with other underlying inflammatory diseases, chronic infections, cancers and for where no cause is found the prognosis may depend on the underlying disease and the condition may recur.
Key points
- HV is usually caused by medications or other underlying diseases.
- Treatment and prognosis depend on identifying the causative factors where possible.