PURPURA, ALLERGIC

General Information

DEFINITION--A common allergic disorder involving sudden bleeding into the skin or intestines.

BODY PARTS INVOLVED

• Joints (usually knees, ankles, hips, wrists and elbows).
• Skin of the legs, thighs and abdomen.
• Gastrointestinal tract.
• Kidneys.

SEX OR AGE MOST AFFECTED--Both sexes; all ages, most common in children and boys twice as often as girls.

SIGNS & SYMPTOMS

• Sore throat about 2 weeks prior to other symptoms.
• Itching skin rash that seems to be just beneath the skin surface. The rash usually consists of large hives with small bruises or blood spots in the centers. The rash is most often on the buttocks and upper thighs in children and on the feet and ankles of adults, but it may be scattered over the body.
• Joint pain and inflammation at the knees, ankles, hips, wrists or elbows.
• Cramping abdominal pain and vomiting.
• Diarrhea; low fever.
• Protein and blood in the urine.

CAUSES--Purpura is probably an autoimmune reaction in the inflamed small blood vessels throughout the body. The allergic trigger is not known, but attacks often follow an upper-respiratory infection or the use of some drugs, especially sulfa drugs.

RISK INCREASES WITH

• Recent illness, especially a bacterial sore throat.
• Use of sulfa drugs.

HOW TO PREVENT

• Don't allow your child to be exposed to respiratory infections, if possible.
• Obtain prompt medical treatment of any bacterial throat infection.
• Avoid the use of any drug that has triggered allergic purpura in your child. Consult the doctor before giving any medication to a child.

What To Expect

DIAGNOSTIC MEASURES--

• Your own observation of symptoms.
• Medical history and exam by a doctor.
• Laboratory blood studies and blood-clotting studies.

APPROPRIATE HEALTH CARE

• Home care after diagnosis.
• Doctor's treatment.
• Care can usually be given at home, but complications may require hospitalization.
• Treatment involves the elimination of any possible offending drug and supportive therapy to relieve symptoms.

POSSIBLE COMPLICATIONS

• Kidney failure, resulting from kidney inflammation and damage.
• Permanent joint deformity.

PROBABLE OUTCOME--Allergic purpura usually lasts 3 to 6 weeks. Some children only have a few spots and fever. Others require hospitalization for severe abdominal pain and kidney inflammation. Most children with allergic purpura recover completely. In a few, however, allergic purpura recurs or persists for years.

How To Treat

GENERAL MEASURES----Use warm soaks (see Soaks in Appendix) to relieve joint pain.

MEDICATION--Your doctor may prescribe:

• Cortisone drugs or immunosuppressive drugs, such as cyclophosphamide, to suppress inflammation. Effectiveness of treatment varies.
• Antihistamines to relieve itching.

ACTIVITY--If the child has fever or pain, encourage bed rest. The child may sit up for meals and walk to the bathroom. When fever and pain are gone, the child may gradually resume normal activities as strength and well-being allow.

DIET--The child should eat a normal, well-balanced diet. Vitamin and mineral supplements should not be necessary unless the child shows evidence of deficiency.

Call Your Doctor If

• Your child has symptoms of allergic purpura.
• The following symptoms occur during treatment: Unrelenting abdominal pain. Blood in the stool. Black, tarry bowel movements. New bleeding under the skin. Blood in the urine.