Allergic Contact Dermatitis From Transient Formaldehyde Exposure in a Traveler: Are All Backpacks Created Equal?

Contact dermatitis is an increasingly common dermatologic condition, and it is generally associated with exposure to an irritant or allergen that causes pruritic skin lesions of varying size and severity. Formaldehyde, frequently found in household products, preservatives, and fabrics, is a common trigger for allergic contact dermatitis (ACD). We report the unique case of an ACD flare in a patient, which was caused by contact with a backpack while he was traveling abroad. The patient's right arm was in contact with the backpack's shoulder straps every time he would put on the backpack. As a consequence, he developed a pruritic erythematous rash on his right arm. The patient had undergone patch testing prior to the trip, which had shown a positive reaction to formaldehyde, among other compounds. The patient started noticing the resolution of the rash once he stopped using this specific backpack.