Epidemiology
- Most commonly associated with a drug hypersensitivity reaction
Etiology
- Blood Products
- Drugs
- Foreign Antisera
- Anti-Thymocyte Globulin (ATG) (see Anti-Thymocyte Globulin, [[Anti-Thymocyte Globulin]]): horse or rabbit-derived antibodies against human T cells
- Onset of symptoms: 8-13 days after ATG
- Crofab (see Crofab, [[Crofab]]): snake antivenin
- Widow Spider Antivenom (see Widow Spider Antivenom, [[Widow Spider Antivenom]])
- Toxic
Physiology
- Type III Hypersensitivity Reaction
- Does not involve a preformed antibody -> requires development of antibody via adaptive immune system
- Drug (as a hapten) binds to a plasma protein
- Time Required for Primary Sensitization to an Offending Agent: 1-3 wks (however, symptoms may develop within 12-36 hrs, if there has been a prior immunizing exposure)
- Role of Circulating Immune Complexes: clinical disease correlates with high levels of circulating immune complexes and decreased C3/C4/CH50 complement components
Diagnosis
- 125I-Labeled C1q Binding Assay: detects high levels of circulating immune complexes
- C3/C4/CH50: markedly decreased
- Direct Immunofluorescence of Skin Bx: imunoglobulin + C3 deposits in walls of small cutaneous blood vessels
Clinical Manifestations
Dermatologic Manifestations
- Serpiginous Erthematous Band Along Sides of Hands/Feet/Fingers/Toes (at junction of palmar and plantar skin surfaces): early clinical sign
- Rash (see Urticaria-Angioedema, [[Urticaria-Angioedema]]): mobilliform (maculo-papular, measles-like) and/or urticarial
Systemic Manifestations
Rheumatologic Manifestations
- Arthralgia: common
- Arthritis (see Arthritis, [[Arthritis]]): uncommon
- Large joint involvement has been reported ATG-associated serum sickness
- Vasculitis (see Vasculitis, [[Vasculitis]]): uncommon
Renal Manifestations
Neurologic Manifestations
Gastrointestinal Manifestations
- Nausea/Vomiting (see Nausea and Vomiting, [[Nausea and Vomiting]]): has been reported with ATG-associated serum sickness
- Melena (see Gastrointestinal Bleed, [[Gastrointestinal Bleed]]): has been reported with ATG-associated serum sickness
Treatment
- Drug-Related Serum Sickness: symptoms usually subside within days after drug withdrawal (may take longer in cases associated with long-acting agents)
References
- Transfusion-induced serum sickness. Transfusion 2009 Feb;49(2):372-45 [MEDLINE]