A man in his mid-20s with a history of atopic dermatitis presented to the emergency department with a 1-week history of a worsening painful and pruritic generalized rash. Examination revealed erythematous erosions on the trunk and limbs with shallow bullae (Figure 1; Supplemental Figure 1, available online at http://www.mayoclinicproceedings.org) and absence of Nikolsky sign.
Figure 1Widespread shallow erosions with collarettes of scale on the left side of the back with a few shallow intact bullae (left lower back) on background erythema.
Swabs were negative for herpes simplex and varicella zoster viruses. Punch biopsy showed superficial acantholysis (Figure 2). Direct immunofluorescence was negative. He was diagnosed with disseminated bullous impetigo and treated with cefadroxil, doxycycline, and topical corticosteroids with acetic acid wet dressings with improvement (Supplemental Figures 2 and 3, available online at http://www.mayoclinicproceedings.org).
Figure 2Photomicrograph showing superficial acantholysis (hematoxylin and eosin stain, original magnification ×100).
Bullous impetigo is a common skin infection in children; disseminated bullous impetigo (defined as more than 10 lesions and involvement of multiple body sites) is reported in children and 1 adult with severe atopic dermatitis.
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Shallow blisters are due to cleavage of desmoglein 1 in skin by Staphylococcus aureus exfoliative toxins at the site of rash, compared with sterile blisters in staphylococcal scalded skin syndrome.Initial misdiagnosis is common; other differential diagnoses include eczema herpeticum, atopic dermatitis flare, staphylococcal scalded skin syndrome, and autoimmune bullous disorders.
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Clinical clues include history of atopy, lack of systemic symptoms, widespread shallow bullae and erosions, and absence of Nikolsky sign. Thorough history, examination, and bacterial and viral swabs aid in diagnosis. Skin biopsy specimens for histopathologic evaluation and direct immunofluorescence should be obtained if immunobullous conditions are considered. Oral antibiotics and treatment of underlying atopic dermatitis lead to rapid improvement. Disseminated bullous impetigo should be considered in patients with a blistering rash and a history of atopic dermatitis.Potential Competing Interests
The authors report no competing interests.
Acknowledgments
We are grateful to the Appignani Lichen Planus Benefactor Gift and the British Association of Dermatologist’s Geoffrey Dowling Fellowship for supporting Dr Xie’s visiting research fellowship.
Supplemental Online Material
Supplemental Figure S1
Supplemental Figure S2
Supplemental Figure S3
References
- Disseminated bullous impetigo and atopic dermatitis: case series and literature review.Pediatr Dermatol. 2020; 37: 103-108
- Disseminated bullous impetigo in atopic dermatitis (‘eczema staphylococcatum’).J Eur Acad Dermatol Venereol. 2021; 35: e280-e282
- Intraepithelial autoimmune blistering dermatoses: clinical features and diagnosis.J Am Acad Dermatol. 2021; 84: 1507-1519
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© 2022 Mayo Foundation for Medical Education and Research
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