Allergic contact dermatitis or contact dermatitis or contact eczema is characterized by eczema lesions appearing on contact with certain non-protein chemicals. It is a delayed, cell-mediated reaction (type IV) [1] according to the Gell and Coombs classification. The allergic reaction does not necessarily occur on first contact. It may appear after several months or years of tolerance. The diagnosis is essentially clinical. The lesions are highly pruritic and may impact the quality of life of the patient [2]. Acute eczema evolves in four successive phases, often intertwined: the erythematous phase characterized by the appearance of an erythematous placard, the vesicular phase characterized by vesicles filled with clear liquid, sometimes confluent in bubbles, the oozing phase characterized by the rupture of vesicles, spontaneously or after scratching, and the crusty or desquamative phase followed by the recovery phase. In the case of persistent exposure to the allergen, the eczema becomes chronic and is characterized by lichenification. Regarding treatment, the detection of the responsible allergen is essential. Several treatments may be proposed. Strong-class dermocorticoids act on the inflammation. Antihistamines are proposed to fight against pruritus. Emollients play an important role in hydration. As for oral corticoids, they are proposed only for severe and extreme cases because of their multiple side effects.

A 41-year-old patient with no notable pathological history presented to the dermatology clinic for the evaluation of bilateral and symmetrical lesions on the armpits evolving for several months. These lesions were lichenified and highly pruritic. Hyperpigmentation was also noted (Fig.1a). A cutaneous biopsy was performed, showing spongiotic dermatosis confirming the diagnosis of eczema. The patient was treated with strong-class dermocorticoids and an emollient with an excellent evolution (Fig. 1b).

Figure 1: Bilateral, symmetrical, and hyperpigmented lesions on the armpits. (b) Significant improvement after three weeks of treatment with dermocorticoids and an emollient.

REFERENCES

1. Seck B, Diallo M, Ndiaye MT, Diop A, Ba ID, Ly F. Atopic dermatitis in Senegalese children with skin phototype VI:Prevalence, clinical features, and risk factors of severity. Our Dermatol Online. 2022;13:359-64.

2. Lambert J. Itch in allergic contact dermatitis. Front Allergy. 2021;2:702488.