Long-term clinical course and prognosis of vaccine-related persistent itching nodules (1997–2019): An observational study

BACKGROUND: Vaccines adsorbed to aluminium can induce long-lasting intensely itching subcutaneous nodules (granulomas) at the injection site as well as contact allergy to aluminium. In clinical trials of a new acellular pertussis vaccine performed in the 1990s (Gothenburg, Sweden) with 76 000 participants, itching nodules were reported in 745 children. A positive patch test to aluminium was verified in 77% of the tested children with itchy nodules. AIM: To describe the long-term clinical course and prognosis of vaccine-related itching nodules caused by aluminium-containing pediatric vaccines and to estimate the risk for new symptoms after future vaccination with aluminium-containing vaccines. METHODS: 745 children with vaccine-related itching nodules were followed by regular interviews/questionnaires for more than 20 years. 723 of them received a booster dose of diphtheria/tetanus vaccine either with or without aluminium adjuvant during the follow-up time. RESULTS: Most study participants (86%) reported a full recovery from their itching nodules after a median duration of 6.6 years. Only a few of the diphtheria/tetanus-booster-vaccinated children (3%) reported mild transient itching and swelling at the new injection site. CONCLUSION: Vaccine-induced itching granulomas caused by an aluminium-adsorbed acellular pertussis toxoid vaccine seem to disappear over time. Future vaccinations with aluminium-adsorbed vaccines can be performed with little risk for new itching nodules later in life.