Serum Sickness Mai Nguyen Mercer University COPHS Doctor of Pharmacy Candidate 2012 June 9, 2011 Preceptor: Dr. Ali Rahimi

Overview Serum sickness is a reaction similar to an allergy. Specifically, type III hypersensitivity reaction to certain medications, injected proteins used to treat immune conditions, or antiserum Antiserum: liquid part of blood that contains antibodies that help protect against infectious or poisonous substances Example: Tetanus vaccine

Introduction of antigen Pathophysiology Introduction of antigen Body’s immune system responds by synthesizing antibodies after 4-10 days Antibody reacts with antigen, forming soluble complexes that may diffuse into vascular walls and may initiate activation of complement

Proteolytic enzymes that can mediate tissue damage are released Pathophysiology Complement-containing immune complexes generate influx of leukocytes into vessel walls Proteolytic enzymes that can mediate tissue damage are released Immune complex deposition + inflammatory response are responsible for vasculitic lesions seen in SS

Causes Antiserum Tetanus or rabies vaccination Medications PCN Sulfa Unlike other drug allergies, which occur very soon after receiving the medication again, SS develops 7-21 days after the first exposure to medication Injected proteins Antithymocyte globulin (ATG) - treat organ transplant rejection Rituximab – mAb treats immune disorders and cancers Blood products

Symptoms Fever Rash Muscle aches Swollen lymph nodes Hives Difficulty breathing Itching Edema Joint pain

Signs and Tests Lymph nodes may be enlarged and tender to touch. Urine may contain blood or protein. Blood tests may show immune complexes or signs of blood vessel inflammation Elevated erythrocyte sedimentation rate Leukocytosis

Treatment Corticosteroid creams or ointments – relieve discomfort from itching and rash Antihistamines – may shorten length of illness and help ease rash and itching NSAIDS – may relieve joint pain Tylenol – helpful in relieving fever and muscle pain Medications causing problem should be stopped and future use should be avoided.

Complications and Prognosis Vasculitis Neuropathy Anaphylaxis Shock Death Most cases are mild and resolve within a few days. Symptoms may persist for several weeks. Fatalities are rare and usually are due to continued administration of the antigen.

References Chen SM. (2010). Serum Sickness in Emergency Medicine. Medscape. Retrieved from http://emedicine.medscape.com/ article/756444-overview Henochowicz, SI. (2011). Serum Sickness. PubMed Health. Retrieved from http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001823/