Associated factors of widespread pattern of dermatitis among patch test population: 12-Year retrospective study

Widespread dermatitis is often associated with diagnostic and therapeutic challenges. Multiple factors influence this widespread pattern of dermatitis. We aim to study the associated factors in patch-tested patients who presented with widespread pattern of dermatitis.

This retrospective, case-control study was conducted on patients with dermatitis who were patch tested during January 2005 to December 2016. The demographic data, patient and family histories, diagnoses, and patch test findings were recorded and analyzed.

Of the 3201 included patients, 645 (20.2%) had widespread pattern of dermatitis. Being male, age >60, and history of either atopic dermatitis (AD) or metal allergy were significantly associated with the widespread dermatitis pattern. A multivariate analysis demonstrated that preservatives were the significant offending allergens, especially methylchloroisothiazolinone/methylisothiazolinone (MCI/MI), and methylisothiazolinone (MI) alone.

Widespread pattern of dermatitis is associated with gender, age, underlying atopic dermatitis and a history of metal allergy. Preservatives are the significant offending allergens of widespread dermatitis, especially MCI/MI, and MI alone. A thorough history taking and patch testing, including preservatives, are necessary to determine the cause of widespread pattern of dermatitis.