What are the signs and symptoms of a serum sickness-like reaction?

From the Guidelines

Serum sickness-like reaction typically presents with fever, rash, and joint pain or swelling that develops 1-3 weeks after exposure to certain medications, and management includes immediate discontinuation of the offending medication, antihistamines for symptomatic relief, and in more severe cases, corticosteroids. The rash is often urticarial (hive-like) or morbilliform (measles-like) and may be accompanied by facial swelling, particularly around the eyes and lips. Patients commonly experience lymphadenopathy (swollen lymph nodes), arthralgia or arthritis (joint pain or inflammation), and sometimes gastrointestinal symptoms like nausea, vomiting, or abdominal pain. In severe cases, patients may develop proteinuria, hematuria, or even neurological symptoms. Common medication triggers include antibiotics (particularly cefaclor, amoxicillin, and other beta-lactams), anticonvulsants, and monoclonal antibodies. This reaction differs from true serum sickness as it doesn't involve immune complexes but rather represents a delayed hypersensitivity reaction.

Key Points

• Symptoms of serum sickness-like reaction include fever, rash, and joint pain or swelling
• The reaction typically develops 1-3 weeks after exposure to certain medications
• Management includes immediate discontinuation of the offending medication, antihistamines for symptomatic relief, and in more severe cases, corticosteroids (such as prednisone 0.5-1 mg/kg/day for 5-7 days with taper) 1
• Most cases resolve within 1-2 weeks after medication discontinuation, and patients should be advised to avoid the triggering medication in the future

Medication Triggers

• Antibiotics (particularly cefaclor, amoxicillin, and other beta-lactams)
• Anticonvulsants
• Monoclonal antibodies

Reaction Characteristics

• Delayed hypersensitivity reaction
• Does not involve immune complexes
• Can be severe and life-threatening in some cases

Treatment Approach

• Desensitization may be performed when the implicated drug is the preferred therapy 1
• Skin testing and risk stratification, or risk stratification without skin testing and challenge, may also be used
• Patients without a convincing clinical history of an HSR do not require desensitization and typically respond well to readministration of the chemotherapeutic agent 1

From the FDA Drug Label

The hypersensitivity reactions reported are skin eruptions (maculopapular to exfoliative dermatitis), urticaria and other serum sickness-like reactions, laryngeal edema and anaphylaxis. Fever and eosinophilia may frequently be the only reaction observed The signs and symptoms of a serum sickness-like reaction include:

• Urticaria
• Fever
• Eosinophilia 2

From the Research

Signs and Symptoms of Serum Sickness-Like Reaction

The signs and symptoms of a serum sickness-like reaction (SSLR) include:

• Dermatological manifestations, primarily maculopapular rashes, which were present in 100.0% of cases 3
• Joint symptoms, such as arthralgia or arthritis, which occurred in 78.7% of cases 3
• Fever, which may be present in some cases 3, 4, 5
• Urticaria or urticarial-like rashes 6
• Angioedema 7, 6
• Gastrointestinal distress 6

Characteristics of Serum Sickness-Like Reaction

SSLR is an adverse reaction mainly to drugs, infectious agents, or vaccines 3

• Antibiotics, particularly beta-lactam antibiotics, such as amoxicillin, are commonly implicated in SSLR 3, 7, 5
• Cefazolin, a first-generation cephalosporin, has also been associated with SSLR 5
• The reaction typically occurs several days after exposure to the offending agent 4, 5
• Corticosteroids are often effective in resolving symptoms 3, 7, 5