Evolution of Aluminium Sensitisation in a French Paediatric Population

In 2018, we reported a high sensitization prevalence for aluminium (21.6%) in our paediatric population [1]. At that time, we related this high level of sensitization in children to the number of vaccinations received in their first year of life. Six years later, we wanted to analyse the evolution of this sensitization in the same paediatric unit.

We used the same methods as the previous study, especially the same collection time of 3 years and the same paediatric department. But we have removed the metallic aluminium from the patch tests and have tested only with the aluminium chloride hexahydrate 2% pet. (Chemotechnique Diagnostics, Vellinge, Sweden) which is a better marker of aluminium sensitisation than metallic aluminium, as demonstrated in our previous study and other authors [1, 2, 3]. From January 2021 to April 2024, all children patch tested for contact allergy were thereby tested with aluminium chloride. The reading was performed according to ICDRG recommendations and by the same dermatoallergologist as in the previous study [1]. We have checked that all children tested had correctly received a classic vaccination schedule.

One hundred fifty‐nine children were patch tested. The mean age was 8.14 years (2–17 years old) with 88 girls (55.35%) and 71 boys (44.65%). A history of atopy was found in 77 cases (48.43%). About 42 children had a positive test reaction to aluminium chloride (26.42%). The mean age of the children with positive reactions was 6.34 years. Of the 42 children who reacted positively to aluminium, 21 (50%) were atopic and only 4 (9.52%) had a history of persistent itching nodules. The evolution of the aluminium sensitisation according to the age of the children was represented in Table 1. Figure 1 illustrates the evolution of the aluminium sensitisation according to the number of vaccine injections.

TABLE 1.

Aluminium sensitization according to the age of the children.

Age	0–4 years old	5–9 years old	10–14 years old	15–20 years old
Aluminium + n (%)	13 (35%)	20 (35%)	8 (13%)	1
Aluminium − (n)	24	37	52	4
Total patient (n)	37	57	60	5

FIGURE 1.

Evolution of the aluminium sensitisation according to the number of vaccine injections.

1. Discussion

We report here the persistence of a high sensitization prevalence for aluminium (26.42%) affecting a very young paediatric population, with or without persistent itching nodules.

In the previous study, we linked this high level of aluminium sensitisation with the vaccination calendar, in relation to the many injections of aluminium‐containing vaccines in the first year of life. This higher level of sensitisation in this study compared to our first study has probably the same origin. We have also found a much higher level of sensitisation compared to others reported [4, 5] This higher sensitisation may be due to our vaccination schedule. For instance, a Swedish study has found only 5.1% of aluminium sensitisation [4]. In comparison with the French vaccination schedule, the Swedish one has fewer mandatory injections, like meningococcus B and C, BCG and VHB [6, 7]. The age of the mandatory vaccines is also different from the French. They recommend the measles, mumps, rubella vaccine at 18 months and 1–2 years compared to 12 and 16–18 months in the French vaccination calendar [6, 7].

In 2014, French children received at least 7 aluminium‐containing vaccines in the first year and at least 11 injections before 16 years old. In 2024, it increased to 11 injections in the first year and at least 14 injections before 16 years old [8]. Indeed, in 2022, the French vaccination calendar has been updated with the addition of aluminium salt‐containing meningococcal B vaccines for the first year of life [9, 10]. Furthermore, aluminium‐containing Human Papillomavirus vaccine has been recommended in teenage boys and girls [2, 11].

In Table 1, we show the decrease of aluminium sensitisation with age. This decrease may correspond with the decrease of vaccine injections with age, as shown in Figure 1. This correlation between sensitisation and vaccination has already been demonstrated in previous studies [12, 13, 14, 15, 16].

In 2022, aluminium salt was named the 2022 American Contact Dermatitis Society Allergen of the Year, and it has been recommended to include aluminium in any baseline patch series for children [4, 12, 13].

In case of aluminium allergy, there is no contraindication for vaccination. Daily life objects or cosmetics containing aluminium should be avoided, such as, for example, deodorants, toothpastes, sunscreens [2, 9, 17].

In conclusion, we report a high persistent prevalence of early sensitisation to aluminium, symptomatic or not, in young children, probably resulting from the number of vaccinations received in their first year. Nevertheless, this sensitisation does not challenge the continuation of the vaccination schedule.

Author Contributions

Laux Miranda: writing – original draft, writing – review and editing, methodology. Letertre‐lelou Oriane: visualization. Naimi Nour: data curation. Segretin Pierre: supervision, visualization. Labrèze Christine: visualization. Milpied Brigitte: methodology, writing – review and editing, writing – original draft, formal analysis.

Conflicts of Interest

The authors declare no conflicts of interest.