Axillary Contact Dermatitis: An Update on Potential Allergens and Management

Symmetrical drug-related intertriginous and flexural exanthema is another condition that presents as intertriginous dermatitis and differs from SCD in that the eruption does not require presensitization; there may be no known prior exposure to the agent causing dermatitis. Historically, SDRIFE was described as baboon syndrome because of its frequent involvement of the buttocks with diffuse, well-demarcated, erythematous dermatitis resembling that of a baboon. This term is no longer used due to its insensitive nature and incomplete depiction of SDRIFE, which can affect body sites other than the buttocks.^68,75,76 Specific criteria to make this diagnosis include sharply demarcated and/or V-shaped erythema of the gluteal/perianal area, involvement of at least 1 other intertriginous or flexural region, symmetry of affected areas, and an absence of systemic symptoms.⁷⁶ There also may be papules, pustules, and vesicles present in affected areas. Symmetrical drug-related intertriginous and flexural exanthema most often is caused by β-lactam antibiotics, but other associated drugs include chemotherapeutic agents, such as mitomycin C.⁷⁶

Histopathology of both SCD and SDRIFE is variable and typically nonspecific, often revealing epidermal spongiosis and a perivascular mononuclear cell infiltrate with occasional neutrophils and eosinophils.⁷⁶ A case of SCD to mercury presenting as intertriginous dermatitis demonstrated a leukocytoclastic vasculitis pattern on biopsy.⁷⁷

Systemic contact dermatitis is diagnosed via a patch test, while SDRIFE typically has a negative patch test result and requires oral rechallenge testing, which reproduces the rash within hours.^78,79

Additional Allergens Causing Axillary ACD

Although fragrance is the most common allergen in deodorants, other ingredients have been shown to cause axillary ACD (Table).^80-90 In addition to these ingredients, allergens not previously mentioned that may be present in deodorants include lanolin, essential oils, and parabens.¹¹ Methylisothiazolinone in laundry detergent also has been found to instigate ACD.⁹¹ Fragrances and preservatives in laundry detergents also may contribute to dermatitis.⁹²

Other products that have caused axillary contact dermatitis include topical exposure to medicaments including clindamycin,⁹³ ethylenediamine in nystatin cream,⁹⁴ methylprednisolone acetate⁹⁵ and dipropylene glycol in a hydrocortisone lotion,⁹⁶ wood dusts from tropical hardwoods,⁹⁷ and tobacco.⁹⁸

Management of ACD

The most effective strategy in the management of patients with contact dermatitis is avoidance of the offending agent. Additionally, clinicians may recommend the use of topical steroids and/or calcineurin inhibitors to hasten resolution.²

For patients with contact dermatitis, a clinician may recommend product substitutions with few potential allergens to use prior to patch testing. Patients with a fragrance allergy should look for products specifically labeled as “fragrance free” rather than “hypoallergenic” or “unscented,” as the latter two may still contain minimal amounts of fragrance.³⁵ Patients should be educated on the functions of the allergens to which they are allergic so they may adequately avoid potential sources of contact.⁹⁹ For suspected textile dye dermatitis, instructing patients to wash clothing before wearing and to avoid synthetic fabrics, dark dyes, and tightly fitted clothing may help.^9,64,65