Serum sickness is a medical condition which in many ways is similar to an allergy. It is an immune response of the body to certain types of medicines or to an antiserum. In medical terminology, it is immune complex type 111 reaction. Serum is a clear fluid which is a component of blood. Serum does not contain cells present in the blood, but it does carry proteins and antigens.
In serum sickness, the body mistakenly identifies proteins present in medicines and antiserum as a harmful foreign substance and triggers immune complex reaction to fight it. In the present age, the most common substance known to cause serum sickness is penicillin, a type of antibiotic.
Serum sickness can also develop by wide range of different antigens such as anti-tetanus serum, antivenin serum after snake bite, or after anti-diphtheria serum injection.It takes at least 7 to 10 days for development of serum sickness after ingestion of medicine or an anti serum injection. Repeated exposure may take less time for manifestation of serum sickness.
What Causes Serum Sickness?
Serum is a clear fluid and it is a part of the blood. It is devoid of blood cells such as red blood cells and white blood cells. However, serum contains antibodies and proteins. Antiserum is produced in laboratories from humans or animals. Its function is to protect a person from certain type of germs he is exposed to. For example, antiserum venom is given after a snake bite. Antiserum injections are also given to patients who are exposed to tetanus and rabies germs.
In serum sickness, the immune system of the body mistakenly recognizes proteins present in antiserum as harmful substances. As a result, an immune complex is formed from the body’s immune element and those from the antiserum. This immune complex of antibody and antigen deposits in tissues cause an inflammatory reaction giving rise to various symptoms of serum sickness.
There are certain medicines which can also cause serum sickness, especially drugs like penicillin, streptomycin, sulphonamides, barbiturates, aspirin, etc. Unlike allergic reaction to any drugs which occur immediately after its exposure, serum sickness takes a longer time to develop.
A person is more at a risk of developing serum sickness if he is injected with antiserum that is known to cause such sickness. It is also possible if a large dose is given, as in the case of snake venom antiserum.
Signs And Symptoms Of Serum Sickness
The symptoms of serum sickness takes time to develop. The first sign of serum sickness is itching and redness at the site where serum is injected. Other important symptoms are:
- Skin rash and welts.
- Fever which may be low grade or high.
- Pain in joints, mostly large joint are first affected. After few days, patient may also experience pain in smaller joints.
- Swelling of regional lymph nodes.
- Swelling of legs, face and arms.
- Gastrointestinal symptoms such as vomiting, diarrhea and cramps in abdomen are not uncommon.
- Flushed face.
- Wheezing sound in chest and discomfort while breathing.
How Long Does Serum Sickness Last & How To Treat It?
Serum sickness develops after delayed period of time. It may take 7 to 10 days for the appearance of symptoms. In some cases, it may be delayed for 3 weeks or 1 month. The illness is seldom serious though it may give rise to much discomfort for the patient. Usually the symptoms of serum sickness improve after 7 to 10 days and the patient may completely recover after 2 to 4 weeks.
Treatment of serum sickness is aimed at alleviating its symptoms. Frequently, physicians prescribe anti histamines and anti inflammatory medications. In more severe cases, corticosteroids are also prescribed. Fever, itching and skin rash may disappear first. Joint pains may take longer time to heal.