Erythema multiforme following pneumococcal vaccination.

Area of Science:

• Immunology and Dermatology
• Vaccinology and Public Health

Background:

• Erythema multiforme (EM) is an immune-mediated mucocutaneous disorder presenting as target-like lesions, often triggered by infections, drugs, or vaccines.
• The 13-valent polysaccharide pneumococcal conjugate vaccine (PCV13) has significantly reduced pneumococcal disease incidence but can cause systemic and cutaneous side effects.

Observation:

• A 2.5-year-old boy developed erythema multiforme (EM) following administration of the 13-valent polysaccharide pneumococcal conjugate vaccine (PCV13).
• The patient presented with characteristic EM lesions, and other potential causative factors for the eruption were ruled out through clinical and laboratory evaluation.

Findings:

• This report details a novel association between pneumococcal vaccination (PCV13) and the subsequent development of erythema multiforme (EM).
• While EM is a known vaccine-associated adverse reaction, this is the first documented case linked to pneumococcal vaccination.

Implications:

• The findings suggest that PCV13 may be an additional trigger for erythema multiforme (EM), expanding the spectrum of known vaccine-related cutaneous reactions.
• Further research is warranted to confirm this association and understand the immunological mechanisms underlying PCV13-induced EM, informing vaccine safety monitoring.