Introduction
Bullous pemphigoid (BP) is a disease of autoimmune origin which is clinically characterized by the appearance of large blisters (known as bullae) on erythematous and pruritic zones. The bullae are preferentially present on the limbs, but any area can be affected. Oral impairment is also possible. From a histological point of view, bullae are explained by the abnormal presence of autoantibodies against two proteins (AgPB230 and AgPB180) between the dermis and the epidermis. For this reason, the histological diagnosis of BP is asserted when subepidermal blisters and linear deposits of immunoglobulin G (IgG) and complement are observed in the basement membrane.
Case Report
This report is a case of BP in a seven-month-old female infant, without any significant medical history, who was referred to the emergency department (ED) for fever, macular erythroderma, and some millimeter-sized vesicles on her hands and feet. The parents reported a severe pruritus. The infant had been seen 48 hours beforehand by her general practitioner, who had diagnosed impetigo and had prescribed amoxicillin-clavulanic acid. The mother had not administered the medication to her child. On the day of the consultation in the ED, the mother asked another practitioner for a second opinion. This doctor, who suspected Steven-Johnson syndrome, referred her to Robert Debré Teaching Hospital’s (Paris, France) ED.
When examined, the infant was afebrile, without hemodynamic failure. The clinical examination showed erythroderma on the whole body, with inconspicuous millimeter-sized vesicles on the palms of the hands and feet soles (Figure 1; color image available as supplementary material [online only]), with small, yellowish oozing crusts. Considering these symptoms, a bullous impetigo was diagnosed and Steven-Johnson syndrome was dismissed in the absence of epidermal peeling. Amoxicillin-clavulanic acid was prescribed for 10 days, a new medical consultation being scheduled after a 48-hour period for a re-evaluation.
Figure 1 Erythroderma without Bullae.
The infant was re-examined 48 hours later. She was febrile with a body temperature of 38.3°C (100.9°F), with no hemodynamic failure. In addition to erythroderma, the clinical examination demonstrated very large bullae on her hands and feet. The bubbles on the feet entirely covered the soles (Figure 2; color image available as supplementary material [online only]). They were popped and the child was hospitalized in the dermatology department.
Figure 2 48 Hours After the First Examination in ED. Note: Large, swollen bullae were observed on the feet, following erythroderma. Abbreviation: ED, emergency department.
The biopsies showed linear deposits of IgG in the basal membrane, and thus physicians could assert the diagnosis of BP. The symptoms went away after a few days following a treatment with topical corticosteroids.
Discussion
As illustrated by this case, physicians working in a pediatric ED must know BP in its broad outline. The differential diagnosis of BP is mainly with other autoimmune bullous diseases, namely linear IgA dermatosis and pemphigus. According to Kong in a retrospective study of 12 patients, the most common disease in children would be linear IgA dermatosis, affecting 41.7% of patients, BP and pemphigus being on equal terms with 16.7% each.Reference Kong, Lim and Chandran 1
Of note, BP is a disease whose prevalence increases with age. In France, while the prevalence estimate is 1.00 out of 40,000 for all ages combined, it is 1.00 out of 3,000 after 70 years of age. Although much rarer, this disease is also present in children. Waisbourd-Zinmman estimates the incidence of childhood BP in Israel at 2.36 out of 100,000 inhabitants per year.Reference Waisbourd-Zinman, Ben-Amitai and Cohen 2 In addition, the disease seems to include certain peculiarities in children when compared to the adults’ form. Thus, for example, more than one-half (58%) of the cases of BP begin before the first year of life, and the predisposition for reaching the extremities is higher in children under one year of age (79% versus 17%). The practitioner must keep in mind certain atypical and serious manifestations affecting children. Akin described the case of a 16-day-old infant clinically presenting BP associated with respiratory distress.Reference Akin, Gunes and Akýn 3 A fiberoptic examination showed bullae in the upper airways and the epiglottis, thus explaining the presented symptomatology.
The French National Authority for Health (HAS; Saint-Denis, France) recommends topical corticosteroids as the first line treatment for BP.Reference Joly 4 Systemic corticosteroids are indicated only in the event of topical corticosteroids’ failure. On a case-by-case basis, other immunosuppressants such as methotrexate, mycophenolate-mofetil (MMF), or azathioprine can be added to systemic corticosteroids. Fine noticed that the three main causes of relapse in the first year were significant dermal involvement prior to treatment, dementia, and high levels of anti-BP180 antibodies (greater than 23 U/mL) after 150 days of treatment.Reference Fine 5 In children, several authors reported cases of BP resistant to treatment with corticosteroids. For example, Ister described the case of a 3-month-old infant who developed BP one week after administration of a hexavalent vaccine.Reference Ister, Pouessel and Ythier 6 The disease resisted local and oral corticosteroids and required the use of immunoglobulins. These allowed a complete control of the disease and the absence of recurrence, including after the next injection of the hexavalent vaccine. In addition, Seminario-Vidal described the case of a child for whom a treatment with MMF was required to control BP resistant to local and systemic corticosteroids.Reference Seminario-Vidal, Sami and Miller 7 The use of this treatment once again allowed a complete control of the disease.
Conclusion
This case shows the importance of the ED physician’s prior knowledge of BP so that a differential diagnosis with other autoimmune diseases can be made.
Supplementary Material
To view supplementary material for this article, please visit https://doi.org/10.1017/S1049023X18000456
