Eczema Coxsackium: Intersection of Hand, Foot and Mouth Disease with Atopic Dermatitis

Dear Editor, A 3-year-old boy presented with occasionally itchy rashes over the bilateral forearms and neck as well as multiple fluid-filled lesions over his hands and feet for 3 days. The mother reported that the child had preexisting scaly, itchy lesions on the bilateral cubital fossa and neck, which were followed by the development of fluid-filled lesions in the same areas. These later spread to involve the bilateral palms and soles. The child has experienced recurrent itchy rashes since the age of one, primarily on the flexor surfaces of the upper and lower limbs, with periods of worsening and improvement depending on the season. There was also a family history of asthma. On examination, there were multiple crusted papules over the neck, bilateral popliteal, cubital fossa, and a few discrete lesions around the oral cavity [Figure 1a and b]. He had multiple elongated vesicles with surrounding erythema over the bilateral hands and feet [Figure 1c]. Pinpoint petechiae were noted over the hard palate, with few superficial ulcers over the buccal mucosa. Dermoscopy of lesions on the flexor aspect of bilateral forearms revealed white scales, serocrusts, and black dots, which are features suggestive of chronic eczema [Figure 2a] and an intact vesicle on the dorsum of the right hand showed a violaceous hue and surrounding erythema suggestive of hand–foot–mouth disease (HFMD) [Figure 2b]. Based on the history and examination findings, the child was diagnosed with hand–foot–mouth disease with eczema coxsackium over preexisting atopic eczema. The patient had a history suggestive of atopy. Laboratory confirmation of the diagnosis by polymerase chain reaction could not be done due to lack of facilities. The patient was treated with antihistamines and topical calamine lotion. Informed consent was obtained from parents.Figure 1: (a) Multiple erythematous to hyperpigmented crusted plaques on bilateral cubital fossa, (b) Crusted plaques, (c) Multiple erythematous vesicles and erosions noted on dorsum of hand and fingersFigure 2: (a) Dermoscopy showing white scales along langers lines and serocrusts, (b) Dermoscopy of an intact vesicle with a violaceous hue and surrounding erythema notedDiscussion Coxsackievirus A16 (CVA16) and human enterovirus 71 are two viruses that frequently cause HFMD. Rarely, CVA4-A7, A9, A10, B1-B3, and B5 might result in HFMD. Self-limiting HFMD begins with a low-grade fever and progresses to oval papulovesicular eruptions throughout the hands, feet, perioral region, knees, buttocks, and oral cavity, along with perilesional erythema.[1] HFMD outbreaks have been reported from various locations in India. Like eczema herpeticum which is attributed to the herpes simplex virus 1, eczema coxsackium was identified as a unique cutaneous manifestation of HFMD characterized by vesicles and erosions in areas afflicted by atopic dermatitis. This term was described during a CVA6-associated North American enterovirus outbreak of 2011–2012.[2] Apart from CVA6, CVA16 has also been implicated in eczema coxsackium cases. In addition, individuals with Darier’s disease, epidermolytic ichthyosis, and HIV infection have been reported to develop eczema coxsackium alongside atopic dermatitis. Eczema coxsackium is treated symptomatically with topical calamine lotion, wet wrap therapy, antihistamines, and antipyretics.[1] This morphology has a startling resemblance to the HSV1-induced eczema herpeticum. It is unclear why only specific viruses, such as HSV1, vaccinia, and currently CVA6, more frequently cause vesicles and erosions in dermatitis-affected areas. In the latest outbreak, the eruption favored previously injured or inflamed sites, as well as areas with AD. Vesicles, bullae, and erosions that appeared where sunburn had previously occurred, diaper dermatitis, irritating dermatitis, healing lacerations, and tinea pedis are a few examples of this phenomenon.[2] The inclination for injury-prone sites may explain why children’s buttocks, palms, and soles are frequently affected by both conventional HFMD and this more severe eruption. It is necessary to be aware of this presentation to make the diagnosis correctly. Declaration of patient consent The authors certify that they have obtained all appropriate consent forms, duly signed by the parent(s)/guardian(s) of the patient. In the form, the parent(s)/guardian(s) has/have given his/her/their consent for the images and other clinical information of their child to be reported in the journal. The parents understand that the names and initials of their child/children will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.