From the Guidelines
Serum sickness-like reaction (SSLR) due to antibiotics is a delayed hypersensitivity reaction that typically occurs 1-3 weeks after starting antibiotic therapy, characterized by fever, rash, joint pain, and sometimes lymphadenopathy, and management involves immediate discontinuation of the offending antibiotic and symptomatic treatment. The most common antibiotics associated with SSLR include cefaclor, amoxicillin, trimethoprim-sulfamethoxazole, and ciprofloxacin 1. Unlike true serum sickness, SSLR does not involve immune complexes or complement activation but represents a T-cell mediated delayed hypersensitivity reaction. Some key points to consider in the management of SSLR include:
- Immediate discontinuation of the offending antibiotic
- Symptomatic treatment with antihistamines for pruritus
- Short courses of corticosteroids (such as prednisone 0.5-1 mg/kg/day for 5-7 days) for severe symptoms
- NSAIDs like ibuprofen (400-600 mg three times daily) may help with fever and joint pain
- Patients who experience SSLR should avoid the triggering antibiotic in the future and should inform all healthcare providers about this reaction, as cross-reactivity within antibiotic classes can occur 1. It's also important to note that the risk of recurrence of an allergic reaction upon re-exposure to the antibiotic or the risk of cross-allergy with other antibiotics depends on several factors, including the type of antibiotic, the severity of the reaction, and the time since the index reaction 1. Overall, the management of SSLR due to antibiotics requires a careful assessment of the patient's symptoms, medical history, and the potential risks and benefits of different treatment options.
From the FDA Drug Label
Cases of serum-sickness-like reactions have been reported with the use of cefaclor These are characterized by findings of erythema multiforme, rashes, and other skin manifestations accompanied by arthritis/arthralgia, with or without fever, and differ from classic serum sickness in that there is infrequently associated lymphadenopathy and proteinuria, no circulating immune complexes, and no evidence to date of sequelae of the reaction While further investigation is ongoing, serum-sickness-like reactions appear to be due to hypersensitivity and more often occur during or following a second (or subsequent) course of therapy with cefaclor
Serum sickness-like reaction due to antibiotics, specifically cefaclor, is a hypersensitivity reaction characterized by:
- Erythema multiforme
- Rashes
- Other skin manifestations
- Arthritis/arthralgia
- Fever (with or without) It differs from classic serum sickness in that it has:
- Infrequent lymphadenopathy
- Infrequent proteinuria
- No circulating immune complexes
- No evidence of sequelae of the reaction 2
From the Research
Definition and Characteristics
- Serum sickness-like reaction (SSLR) due to antibiotics is an adverse reaction characterized by the presence of rash, arthralgia/arthritis, and occasionally fever 3.
- The clinical features of SSLR include cutaneous reactions, arthralgias, and moderate hyperthermia 4.
- Dermatological manifestations, primarily maculopapular rashes, are present in most cases, while joint symptoms occur in a significant proportion of patients 3.
Implicated Agents
- Antibiotics, particularly beta-lactam antibiotics such as amoxicillin, are commonly associated with SSLR 3.
- Cefaclor, a semisynthetic cephalosporin, has been linked to SSLR in children 4, 5, 6.
- The incidence of SSLR with cefaclor is estimated to be 0.024-0.2 percent per drug course 4.
Age and Susceptibility
- Children under five years of age are more susceptible to SSLR due to antibiotics, particularly cefaclor 4, 6.
- Adults can also experience SSLR, but the reaction is more common in children 3.