Contact allergy in children with and without atopic dermatitis: An Italian multicentre study

Abstract

Background Contact allergy and atopic dermatitis (AD) are both common inflammatory T cell‐mediated diseases and many factors may influence the prevalence of contact allergy in AD patients. In children, their possible correlation was debated with conflicting results. Objectives The present study aimed to assess the prevalence of contact sensitivity in children and to investigate the association with AD. Materials and methods A retrospective multicentre study on children aged from 0 to 14 years patch tested between January 2017 and December 2018 was performed. Children were consecutively patch tested with the SIDAPA (Società Italiana Dermatologia Allergologica Professionale Ambientale) baseline series. Results Among the 432 children investigated for contact allergy, 125 (28.9%) showed a positive reaction to at least one of the allergens tested, with a higher prevalence of positive patch test reactions in girls (32.3%) than in boys (25.0%). The most frequent contact allergens were nickel sulphate (10.2%), cobalt chloride (6.7%), methylisothiazolinone (3.7%), fragrance mix‐2 (3.2%), potassium dichromate (2.8%), fragrance mix‐1 (2.1%) and methylchloroisothiazolinone/methylisothiazolinone (2.1%). One‐hundred‐three children (23.8%) suffered from AD showing a higher prevalence of positive patch test (36.9%) compared to children without AD (26.4%). Conclusions Despite the topic being still controversial, the present study suggests a consistent prevalence of contact allergy among children with higher sensitivity rate among children with AD than without AD.

Patch testing with cobalt in children and adolescents: North American contact dermatitis group experience, 2001–2018

“…We found that cobalt reactions in children were not associated with sex, atopic history, race or employment. This is in contrast to other studies which found that children with cobalt allergy are more likely to be female 4 and have a history of atopic dermatitis 16 or atopy. 8 A Polish study of 9320 children found that every second child with atopic eczema has a positive patch test result, and every third child ultimately was diagnosed with ACD.…”

Children atopic dermatitis: Diagnosis, mimics, overlaps, and therapeutic implication

“…39,41 Patients with AD who develop EH tend to have more severe AD, earlier-onset AD, high total serum immunoglobulin E/peripheral eosinophils, and presence of other atopic diseases such as food allergies and asthma, as compared to their AD counterparts without EH. 39,41 It may be confused with impetigo, especially in patients with a history of severe AD (EH incognito) or in the early stages with AD itself. 39,41 Bacterial positivity on skin culture does not exclude EH.…”

“…Impetigo is a superficial bacterial infection caused mainly by Staphylococci and Streptococci, and takes the form of pain, erythema, and serum scabs 39 . It may therefore be confused with AD or coexist with it 39 .…”

“…Bacterial positivity on skin culture does not exclude EH. The diagnosis can be confirmed by PCR or Tzank smear 39,41 …”

“…An immunodeficiency syndrome must be hypothesized when chronic eczematous dermatitis is associated with secondary infections or other specific signs 30 . Thus, the correct workup in suspecting such diseases includes growth curve assessment, targeted laboratory and imaging tests, and genetic testing 39,45 . It is important to emphasize that the mere finding of elevated IgE levels does not entitle the patient to be immediately classified as HIES 30,45,46 .…”