Serum Sickness

A person with serum sickness has an immune system reaction after taking a medication or similar substance. The immune system makes proteins called antibodies to attack the medication. This reaction of the immune system causes inflammation throughout the body and the symptoms of serum sickness. In most cases, when the person stops using the medication or other substance, the symptoms go away.

Usually, it takes 1 to 2 weeks after being exposed to the substance before symptoms of serum sickness occur. Signs and symptoms may include:

• fever
• skin lesions or a rash, which may occur all over the body
• joint pain
• itching
• hives, or small areas of skin swelling
• swollen lymph glands
• malaise, or "feeling lousy"
• nausea, vomiting, or diarrhea
• headache

Serum sickness is most often caused when a person takes or receives one of the following substances:

• antibiotics, especially medications in the penicillin or sulfa class, or one called streptomycin
• aspirin
• propylthiouracil, a medication used to treat high thyroid hormone levels, a condition called hyperthyroidism
• antithymocyte globulin (ATG), which is sometimes used to prevent rejection after an organ transplant
• horse antiserum, a treatment that uses antibodies taken from horses to treat certain conditions (for example, poisonous snake and spider bites). This association accounts for the origin of the term "serum" sickness.

Other substances may also cause this condition.

There is no way to prevent serum sickness. A person who get serum sickness once should avoid the medication or other substance in the future. This will help prevent serum sickness from happening again.

The diagnosis of serum sickness is made when someone has been exposed to one of the substances known to cause this condition and has the usual signs and symptoms during examination.

In most cases, there are no long-term effects from serum sickness. In rare cases, mild kidney or nerve damage may occur.

Serum sickness is not contagious.

The most important treatment is to stop taking the substance that caused the serum sickness. Antihistamines, such as diphenhydramine, may be given to reduce itching and other uncomfortable symptoms. Corticosteroids, such as hydrocortisone, may also be given to reduce inflammation. This may be given as a pill or as a skin cream for a rash. Both of these treatments may lessen the duration or intensity of the illness. Pain medications, such as acetaminophen, can be given for joint pain.

Antihistamines can cause dry mouth and drowsiness. Corticosteroid creams in some cases can thin the skin and cause lighter colored areas to form. Corticosteroid pills can cause weight gain, stomach upset, and other side effects.

A person with serum sickness usually recovers completely within a week. The medication or other substance that caused serum sickness should not be taken again, even years later. In rare cases, nerve or kidney damage may occur and require ongoing treatment.

Any new or worsening symptoms should be reported to the healthcare professional.