DesCripTionA 5-month-old woman presented with a 1-week history of a bullous eruption that started at acral sites and spread centrally. There was no preceding illness and she had taken no medications. Her last vaccination was at 3 months old per UK immunisation schedule. On examination, her temperature was 38°C and weight was 7.6 kg. She appeared well but had widespread intact and deroofed bullae with an erythematous base predominantly affecting acral sites with no mucosal involvement (figure 1). Investigations revealed an eosinophilia of 1.33×10 9 /L with normal C-reactive protein. Viral PCR of blister fluid was negative for herpes simplex virus type 1 (HSV1), HSV2 and varicella-zoster virus. A skin biopsy showed a dense mixed inflammatory cell infiltrate in the papillary dermis. Direct immunofluorescence microscopy showed linear deposition of IgG and C3 along the basement membrane. Indirect immunofluorescence on salt split skin localised to the roof and ELISA demonstrated antibodies against bullous pemphigoid (BP)180 at 145 U/mL only. The patient was treated with oral flucloxacillin (62.5 mg four times a day; 1 week), oral prednisolone at 4 mg once daily (0.53 mg/kg/day), ranitidine 4 mg three times daily, Dermol 500 lotion and topical Fucibet cream (fusidic acid 2% and betamethasone 0.1%) twice daily. Oral erythromycin 125 mg twice daily was added 1 week later as a steroid sparing agent but was switched to clarithromycin 25 mg twice daily (half of antimicrobial dose) due to 2 weeks of diarrhoea. By week 10, the infant's weight had increased to 8.33 kg (above 50th centile). Her oral prednisolone was gradually reduced to 1.5 mg/day (0.18 mg/kg/day), her clarithromycin dose increased to 75 mg/day and the patient remained blister free since then (figure 2). Prednisolone was stopped completely at the age of 12 months and clarithromycin was discontinued 3 months later after completion of her 12-month immunisations, which were given separately at fortnightly intervals.A literature review identified 88 cases of infants with BP (age range 6 weeks to 12 months).1 2 In 22/88 (25%) cases a vaccination was given prior to (1 day to 1 month) the onset of a bullous eruption. Two cases reported a relapse following revaccination.1 Seventy-three out of 88 (82.9%) cases were treated with systemic corticosteroids (prednisolone at 1-3 mg/kg/day, methylprednisolone at 0.5-3 mg/kg/day, betamethasone at 0.3-2 mg/ kg/day, deflazacort at 1-3 mg/kg/day). The main images in… steroid sparing agent used was dapsone (21/88 cases; 23.9%) at 0.5-2 mg/kg/day. Other steroid sparing agents used included erythromycin, intravenous immunoglobulins, sulfapyridine, mycophenolate mofetil, rituximab, nicotinamide, ciclosporin, azathioprine, cyclophosphamide and omalizumab.Macrolides' mechanism of action on reducing inflammation in bullous dermatoses may include inhibition of the proinflammatory interleukin-6 and interleukin-8 cytokines and the inhibition of eosinophil recruitment.3 Prognosis of infantile BP is excellent although complete remission can...
