Neomycin: sources of contact and sensitization evaluation in 1162 patients treated at a tertiary service

Contact allergy to neomycin in consecutively patch tested Danish eczema patients from 2000 to 2023: A cross-sectional study

BACKGROUND

Neomycin is an aminoglycoside antibiotic that may cause contact allergy. It was withdrawn as a medicine for human use in Denmark in October 2009 but is still found in some vaccines.

OBJECTIVES

To identify time trends in contact allergy to neomycin in the period from 2000 to 2023.

METHODS

A cross-section study of patients ≥18 years consecutively patch-tested with neomycin sulfate (20% in pet.) at Gentofte Hospital, Denmark, during the period 2000-2023 was conducted.

RESULTS

The overall prevalence of contact allergy to neomycin was 1.4%. The prevalence was significantly lower in the period '2010-2023' (1.2%) than in '2000-2009' (1.8%) (p < 0.005). Contact allergy to neomycin was significantly positively associated with facial dermatitis and age >40 years, and significantly negatively associated with occupational dermatitis and hand dermatitis. No changes in sex, occupational dermatitis, atopic dermatitis, hand dermatitis, leg dermatitis, facial dermatitis, or age > 40/≤40 (the MOAHLFA-index) were identified when comparing neomycin contact allergic-patients in the two periods '2010-2023' and '2001-2009'.

CONCLUSION

Neomycin is a rare cause of contact allergy in Denmark with a significantly lower prevalence following its withdrawal as a medicinal product for human use in Denmark in 2009.

Pharmacovigilance in Vaccines: Importance, Main Aspects, Perspectives, and Challenges-A Narrative Review

Pharmacovigilance plays a central role in safeguarding public health by continuously monitoring the safety of vaccines, being critical in a climate of vaccine hesitancy, where public trust is paramount. Pharmacovigilance strategies employed to gather information on adverse events following immunization (AEFIs) include pre-registration data, media reports, clinical trials, and societal reporting. Early detection of AEFIs during clinical trials is crucial for thorough safety analysis and preventing serious reactions once vaccines are deployed. This review highlights the importance of societal reporting, encompassing contributions from community members, healthcare workers, and pharmaceutical companies. Technological advancements such as quick response (QR) codes can facilitate prompt AEFI reporting. While vaccines are demonstrably safe, the possibility of adverse events necessitates continuous post-marketing surveillance. However, underreporting remains a challenge, underscoring the critical role of public engagement in pharmacovigilance. This narrative review comprehensively examines and synthesizes key aspects of virus vaccine pharmacovigilance, with special considerations for specific population groups. We explore applicable legislation, the spectrum of AEFIs associated with major vaccines, and the unique challenges and perspectives surrounding pharmacovigilance in this domain.

Gender differences in allergic contact dermatitis to common allergens

BACKGROUND

Gender-based differences in skin structure, physiology, and allergen exposure can influence contact dermatitis development.

OBJECTIVE

This study investigated the differences and trends in contact sensitizers, focusing on the top 10 allergens and personal care product (PCP) contact allergies from a gender perspective.

METHODS

We conducted a retrospective chart review of 5998 patients undergoing patch testing at an occupational and contact dermatitis clinic in a Thai, university-based, tertiary referral hospital from January 2001 to December 2021. Patients' characteristics and patch test results were collected.

RESULTS

Females had a higher positive patch test rate than males (71.8% vs. 65%, p < 0.001). However, males showed a greater prevalence of occupationally related allergic contact dermatitis (15.9%). Multivariate analysis revealed associations between being female and allergies to colophonium (aOR 1.46, 95% CI 1.07-1.99, p = 0.019), formaldehyde (aOR 1.97, 95% CI 1.17-13.31, p = 0.010), fragrance mix I (aOR 1.66, 95% CI 1.34-2.07, p < 0.001), MCI/MI (aOR 2.55, 95% CI 1.90-3.44, p < 0.001), neomycin (aOR 4.15, 95% CI 2.54-6.80, p < 0.001), and nickel (aOR 2.62, 95% CI 2.17-3.15, p < 0.001). Conversely, being male correlated with allergies to carba mix (aOR 0.51, 95% CI 0.41-0.64, p < 0.001), epoxy resin (aOR 0.26, 95% CI 0.14-0.47, p < 0.001), n-isopropyl-n-phenyl-4-phenylenediamine (aOR 0.41, 95% CI 0.20-0.83, p = 0.014), paraben mix (aOR 0.42, 95% CI 0.32-0.56, p < 0.001), and potassium dichromate (aOR 0.70, 95% CI 0.58-0.84, p < 0.001). Positive reactions to PCPs stood at 13% overall (males 17.1%, females 12.2%, p < 0.001).

CONCLUSIONS

Gender plays a pivotal role in contact dermatitis. This work emphasises the importance of considering gender-specific factors when diagnosing and managing contact allergies.

The new Italian SIDAPA Baseline Series for patch testing (2023): an update according to the new regulatory pathway for contact allergens

Allergic contact dermatitis (ACD) is a common inflammatory skin disease caused by delayed hypersensitivity to chemical and biotic contact allergens. ACD significantly affects the patients' quality of life negatively impacting both occupational and non-occupational settings. Patch testing is the gold standard diagnostic in vivo test to precise the ACD etiology and to correctly perform prevention. According to the Italian Medicines Agency (AIFA) legislative decree no. 178 of 29th May 1991, allergens are defined as medicines and therefore they are subject to strict regulation. In 2017, AIFA (decree no. 2130/2017) started a procedure to regulate contact allergens on the Italian market and actually the contact allergens temporarily authorized are reported in AIFA decree no. 98/2022, valid until November 2023. The availability on the market of contact allergens to diagnose ACD and continuous updating on the basis of new epidemiological trends are mandatory, jointly with the continuous update of the baseline and integrative series for patch testing. For this reason, the scientific community represented in Italy by the Skin Allergies Study Group of SIDeMaST (Italian Society of Dermatology and Venereology) and SIDAPA (Italian Society of Allergological, Occupational and Environmental Dermatology) are constantly working, in close relationship with the European scientific communities with large expertise in this important sector of the modern Dermatology. Herein, we report the setting up of regulatory legislation by AIFA and the new Italian Adult Baseline Series for patch testing.