Pityriasis lichenoides et varioliformis acuta after influenza vaccine

Area of Science:

• Dermatology
• Immunology
• Vaccinology

Background:

• The exact cause of pityriasis lichenoides remains unknown.
• Pityriasis lichenoides (PL) is theorized to be an inflammatory reaction to external triggers like infections, drugs, or vaccines.
• Previously, only the Measles, Mumps, and Rubella (MMR) vaccine has been linked to PL in medical literature.

Observation:

• A 12-year-old male developed a rash of erythematous papules on his trunk, limbs, and abdomen.
• The patient experienced systemic symptoms alongside the skin lesions.
• The onset of symptoms occurred five days post-Influenza vaccination.

Findings:

• This case presents the first documented instance of pityriasis lichenoides et varioliformis acuta (PLEVA) following Influenza vaccination.
• The clinical presentation included crusting on some papules.

Implications:

• This case suggests a potential association between Influenza vaccines and the development of PLEVA.
• Further research is warranted to investigate the immunological mechanisms linking Influenza vaccination to PLEVA.
• This finding may inform future vaccine safety monitoring and etiological studies of PL.