Chromate-Induced Allergic Contact Dermatitis Treated With Dupilumab

Given the frank presentation and history of dermatitis only in areas where the patient was exposed to cement dust, the patient was not patch tested for chromium. Because he had not shown any clinical improvement in the past with ultra-high potency topical steroids, topical therapy was not reattempted. Due to his past history of viral hepatitis, methotrexate was considered but ultimately not pursued as a treatment option. Consequently, the patient was started on dupilumab, and received one loading dose of 600 mg. After a misinterpretation of the recommended dosing, the patient continued the 600 mg dose every two weeks for 2 months, at which time he presented for a follow up visit at which his dupilumab dose was decreased to 300 mg every two weeks. At that point, the patient’s dermatitis had completely resolved (Figure 4), and he reported no adverse events (and, in particular, no conjunctivitis) throughout the treatment course. Though the patient’s occupational exposure to chromate as a cement mason did not change, the patient’s dermatitis remained clear for the next 18 months to date (July 2020).

Clinically, chromate allergy appears as a severe, sometimes widespread, very persistent dermatitis, and is considered to have a relatively poor prognosis, often with therapeutic recalcitrance.⁷ Commonly used treatments for chromate induced ACD include emollients, topical corticosteroids, and topical calcineurin inhibitors.

Treatments for persistent or severe chromate-induced contact dermatitis include phototherapy and immune-modulating treatments such as azathioprine, cyclosporin and methotrexate. Until recently, when these options failed, avoidance was the only long-term management strategy available, often with negative ramifications on the livelihoods of patients who are occupationally exposed to chromate.

The case we present provides a novel treatment approach for a rare form of ACD that has the ability to significantly impact the quality of life of those affected. Dupilumab is commonly used in the treatment of atopic dermatitis (AD), a helper T-cell 2 (TH2) axis-predominant immune disorder. Dupilumab acts as an IL-4 receptor antagonist and prevents the IL-4 and IL-13- mediated inflammatory responses seen in AD. Although ACD is considered predominantly a helper T-cell 1 (TH1)-mediated process, certain allergens sensitize via the induction of the TH2 pathways.^8,9 Dupilumab may be effective in the inhibition of allergens that elicit a TH2-mediated, IL-4 dependent ACD.⁸The ability of dupilumab to treat chromate-induced ACD in our patient also suggests that IL-4 or IL-13 may play a role in ACD. The role of IL-4 in ACD was confirmed in IL-4 knockout mice, which still have the ability to elicit contact sensitivities to oxazolone but not 2,4,6-trinitrochlorobenzene, a contact allergen with a TH2-mediated sensitization pathway.^8,10Dupilumab may be an alternative treatment option for those suffering from chromiuminduced ACD that is recalcitrant to even ultra-high potency topical corticosteroids.