What is Hypersensitivity Vasculitis or Allergic Vasculitis?
Inflammation of blood vessels is known as vasculitis where there is damage to the blood vessels by scarring, thickening and weakening of the vessel walls. There are different types of vasculitis; some of which are acute and some are chronic. Hypersensitivity vasculitis or allergic vasculitis is one such acute type of vasculitis that is characterized by redness or inflammation of the skin occurring after coming in contact with an allergen or irritating substance; hence the name hypersensitivity vasculitis or allergic vasculitis.
Patient has appearance of red spots on the skin, usually which are palpable purpura that are raised spots, red in color and can darken to a purple color. Patient can also have other types of rashes.
Treatment of hypersensitivity vasculitis or allergic vasculitis depends on the cause and is aimed at relieving the patient's symptoms.
Cause of Hypersensitivity Vasculitis or Allergic Vasculitis
Hypersensitivity vasculitis or allergic vasculitis can occur from medication, infection or some foreign object to which the patient experiences an allergic reaction to. However, most of the hypersensitivity vasculitis or allergic vasculitis occurs from drug interaction. It can also occur in conjunction with certain viruses or infections. Whereas, in some cases, the exact cause of hypersensitivity vasculitis cannot be found.
Trigger Factors for Hypersensitivity Vasculitis or Allergic Vasculitis
Medications: Common triggers for hypersensitivity vasculitis or allergic vasculitis are a reaction to a drug. Some of the common drugs which are associated with hypersensitivity vasculitis are: penicillin, some antihypertensive medications, sulfonamide and phenytoin (anti-epileptic medication)
Infections: Hypersensitivity vasculitis or allergic vasculitis can also be triggered by viruses, such as hepatitis B & C or HIV and chronic bacterial infections.
Symptoms of Hypersensitivity Vasculitis or Allergic Vasculitis
The term "vasculitis" refers to inflammation and damage of the blood vessel. This inflammation and damage is the primary indication of vasculitis. The characteristic skin rash, which is the "palpable purpura," can appear as multiple spots which can be red or purple in color. They are commonly seen on legs, torso and buttocks. Patient may also have blisters or hives on the skin as a result of an allergic reaction.
Some of the less common signs and symptoms of hypersensitivity vasculitis include: Joint pain, enlarged lymph nodes and kidney inflammation (rarely).
If the primary cause of hypersensitivity vasculitis is drug interaction, then symptoms usually appear within a week to 10 days of the exposure to the medicine. Some patients can develop symptoms as early as two days after taking the culprit medicine.
Diagnosis of Hypersensitivity Vasculitis or Allergic Vasculitis
The American College of Rheumatology has put forth a set of criteria that should be met with for diagnosis of hypersensitivity vasculitis or allergic vasculitis. These criteria are:
- The patient must be older than 16 years of age.
- Presence of a skin rash which can be palpable purpura or maculopapular.
- Having taken a medicine before the development of the rash.
- Biopsy taken of the skin rash reveals presence of white blood cells surrounding the blood vessels
For further diagnosis, the doctor will also conduct medical history and physical exam of the patient. The symptoms of the patient are assessed carefully and the doctor asks questions about the patient's medication history. A biopsy is taken from the skin rash and sent to the lab for further analysis. Other blood tests, such as erythrocyte sedimentation rate (ESR) are also done to find out the degree of inflammation.
Diagnosis and also the treatment of hypersensitivity vasculitis depend on the cause and whether there is infection or inflammation of other organs.
Treatment of Hypersensitivity Vasculitis or Allergic Vasculitis
Hypersensitivity vasculitis or allergic vasculitis does not have any cure as such. The aim of treatment is to manage and alleviate the patient's symptoms.If a medication is causing the hypersensitivity vasculitis or allergic vasculitis, the patient is told to stop taking that medication after appropriate doctor's recommendation. After this, the symptoms should abate within a few weeks.
Anti-inflammatory medication can also be prescribed to help relieve the inflammation in the blood vessels.
If symptoms are not relieved with anti-inflammatory medications, then corticosteroids are prescribed which reduce inflammation by suppressing the immune system. However, corticosteroids should be used with caution, as they have various side effects such as weight gain, acne and mood swings, especially if they are taken long term. Lowest dose possible is prescribed of corticosteroids.
Complications & Prevention of Hypersensitivity Vasculitis or Allergic Vasculitis
Scarring from the rashes can occur depending on the severity of the hypersensitivity vasculitis. This occurs as a result of permanently damaged blood vessels.
Rarely, inflammation of the kidneys can occur in patients who are suffering from hypersensitivity vasculitis. This occurs from long term exposure to certain drugs or infections which affect kidney health. The symptoms of kidney inflammation often go unnoticed. Diagnosis of a kidney problem can be made from examination of urine sample for evidence of protein or blood in the urine.
There is a chance of recurrence of hypersensitivity vasculitis if the patient is again exposed to the offending drug, foreign object or infection. To prevent hypersensitivity vasculitis from recurring, it is best to avoid known allergens.