Serum sickness refers to a set of symptoms that occurs when a person's immune system reacts to a medication or other similar substance. It is a type of allergic reaction.
What is going on in the body?
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.
What are the causes and risks of the condition?
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
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.
What can be done to prevent the 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.
How is the condition diagnosed?
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.
Long Term Effects
What are the long-term effects of the condition?
In most cases, there are no long-term effects from serum sickness. In rare cases, mild kidney or nerve damage may occur.
What are the risks to others?
Serum sickness is not contagious.
What are the treatments for the condition?
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.
What are the side effects of the treatments?
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.
What happens after treatment for the condition?
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.
How is the condition monitored?
Any new or worsening symptoms should be reported to the healthcare professional.
Harrison's Principles of Internal Medicine, 1998, Fauci et al.