Eczema complicated by allergic contact dermatitis to topical medications and excipients

A review of contact dermatitis

“…Because of these exposures, they may be at increased risk for sensitization from these products, including topical corticosteroids (TCS), and "bland" emollients, as they may still contain allergens, such as propylene glycol (PG), sorbitan esters, lanolin, fragrance, and preservatives. 13 In the elderly population, relevant allergens may be fragrance mix, nickel, and Balsam of Peru, and dermatitis may present as stasis dermatitis (SD) or chronic venous leg ulcers, rather than a typical localized CD. 14 In addition, some studies suggest increased filaggrin loss-offunction mutation in CD, particularly with nickel sensitization and hand eczema, which is a phenotype that may represent contributions of both atopic and contact dermatitis.…”

“…PG is also present in other topical anti-inflammatories, such as the preparations of pimecrolimus and crisabarole, which are used to treat AD and other inflammatory skin disorders. 13,48 Patients with PG sensitization are more likely to have atopy, and 20.5% have underlying AD. 49 PG itself may be a skin irritant resulting in ICD in patients with an already compromised skin barrier.…”

“…Other excipients found in topical steroids, which may rarely cause allergy, are sorbitan esters, such as sorbitan sesquioleate. 13…”

“…They are a relevant allergen in the AD and elderly population, particularly in those with lower extremity venous SD, in which sensitization rates may be as high as approximately 19% to 33% because of a phenomenon known as the lanolin paradox, in which lanolin normally is a weak sensitizer of normal skin, but can sensitize damaged skin more readily. 13,14,51 The allergenic portion of lanolin is attributed to alcoholic fractions, and as such, wool alcohols or Amerchol should be used for lanolin patch testing rather than pure lanolin. 51…”

“…59 The metabolites of steroids, steroid glyoxals, are highly lipophilic allergens that can penetrate the stratum corneum readily. 13 Patch test interpretation for steroids should be delayed to 7 days owing to the potential for initial response to be suppressed by the anti-inflammatory effects of the medication. 2 A phenomenon known as the edge effect can be seen, in which the borders of the patch test site are positive, whereas the skin within the chamber remains negative (Fig 1).…”