From the Guidelines
Serum sickness-like reaction is a delayed hypersensitivity reaction that typically occurs 7-14 days after exposure to certain medications, most commonly antibiotics like cephalosporins, penicillins, and sulfonamides, as supported by the most recent study 1. This reaction presents with a range of symptoms, including:
- Fever
- Skin rash, often urticarial or morbilliform
- Joint pain and swelling
- Lymphadenopathy
- Malaise
- Occasionally, gastrointestinal symptoms
Unlike true serum sickness, which is caused by foreign proteins, serum sickness-like reaction is triggered by medications and doesn't involve immune complex formation with complement activation. The pathophysiology of this reaction is complex and involves a cell-mediated immune response, as described in the study 1.
Treatment of serum sickness-like reaction involves:
- Immediately stopping the offending medication
- Providing symptomatic relief with antihistamines for itching
- Using NSAIDs for joint pain and fever
- In severe cases, a short course of corticosteroids, such as prednisone 0.5-1 mg/kg/day for 5-7 days with a taper, may be necessary, as suggested by the study 1.
It is essential to note that the condition typically resolves within 1-2 weeks after discontinuing the triggering medication, but patients should be advised to avoid the offending drug in the future as subsequent exposures can cause more severe reactions. The study 1 emphasizes the importance of a thorough clinical evaluation and proper management to improve patient outcomes.
Key considerations in managing serum sickness-like reactions include:
- Accurate diagnosis and identification of the offending medication
- Prompt discontinuation of the medication
- Symptomatic treatment and supportive care
- Patient education on avoiding future exposure to the offending medication, as recommended by the study 1.
From the Research
Definition and Characteristics
- Serum sickness-like reaction (SSLR) is an immune response characterized by rash, polyarthralgias, inflammation, and fever 2, 3.
- It is a type III hypersensitivity reaction mediated by immune complex deposition with subsequent complement activation, small-vessel vasculitis, and tissue inflammation 4.
- SSLR is commonly attributed to antibiotics, anticonvulsants, and anti-inflammatory agents, but can also be caused by other medications such as clarithromycin 5 and D-mannose 3.
Clinical Presentation
- Key features of SSLR include fever, rash, polyarthralgia or polyarthritis, and subcutaneous soft tissue swelling 2.
- Symptoms can also include generalized body aches, shortness of breath, and joint pain 5.
- SSLR is usually self-limiting, with symptoms lasting only 1-2 weeks before resolving, but can be severe and prolonged in some cases 4.
Diagnosis and Treatment
- Diagnosis of SSLR is made based on clinical evidence and biological plausibility, and can be confirmed by a graded oral challenge (GOC) in some cases 6.
- Treatment of SSLR typically involves cessation of the offending medication, anti-histamines, non-steroidal anti-inflammatories, and glucocorticoids 2, 3, 5.
- Accurate diagnosis and prompt treatment can produce complete recovery, and clinicians should be aware of the diverse triggers of SSLR and the importance of prompt identification and management to enhance patient safety 3, 4.