The diagnosis of CBDC is clinically suspected in a child presenting with an abrupt onset of tense, clear, or hemorrhagic vesicles and arciform or annular bullae often arising around resolving lesions. These characteristic arciform or annular bullae have been described as a “string of pearls,” “cluster of jewels,” or “rosette pattern.” Younger children more often have the classic distribution of facial and perineal lesions, whereas older children are more likely to present with a generalized eruption [2]. In severe cases, mucous membranes may be involved.

Patients with CBDC are often initially diagnosed with bullous impetigo and in fact their skin lesions may well be secondarily impetiginized. A treatment course of oral antibiotics has often been implemented without success or with limited improvement when the diagnosis is questioned. In cases where a brief course of oral antibiotics has led to improvement, recurrence is the rule.

In spite of the characteristic history and clinical findings, a skin biopsy for confirmation with direct immunofluorescence is recommended. Indirect immunofluorescence testing is helpful especially to rule out other autoimmune blistering disorders such as epidermolysis bullosa acquisita (EBA), which may present in a similar fashion.

Antibiotics, which have been used with reported success in the treatment of CBDC, include erythromycin, dicloxacillin, oxacillin, and trimethoprim-sulfamethoxazole. The mechanism of action is presumably through anti-inflammatory effects [3]. Erythromycin may lead to some initial improvement and can be useful to try while awaiting results of a workup; however, it is unlikely to provide sustained improvement in CBDC [4]. Also, gastrointestinal upset is a common side effect of erythromycin therapy and so may not be well tolerated in a number of patients. Successful treatment with dicloxacillin and oxacillin, both at doses of 50 mg/kg daily, has been described. Potential side effects include gastrointestinal intolerance, urticaria and other allergic reactions, and occasionally transient hepatic dysfunction [5]. Although improvement with trimethoprim-sulfamethoxazole [6] has been reported in a single patient, the risks of severe allergic reactions must be considered. A benefit of treatment with antibiotics is that it generally does not require blood monitoring which is particularly advantageous in the treatment of children.

Systemic corticosteroids are often implemented for symptomatic control at the onset of disease and periodically during flares. Given the side effect profile of corticosteroids especially immunosuppression, adrenal suppression, and bone effects, alternative options are recommended as soon as possible. Serious side effects of systemic steroids may also occur with a short treatment course. Rebound flares may also occur with abruptly halting systemic steroid therapy and so tapering is recommended. As an alternative adjunctive therapy, topical steroids may be considered for newly developing lesions; however, it should not be applied to erosions or non-intact skin.

The treatment considered to be the drug of choice for patients with CBDC is dapsone. Testing for glucose-6-phosphate dehydrogenase (G6PD) deficiency is indicated prior to initiation of dapsone as patients with this deficiency are at higher risk of the life-threatening side effect of hemolysis. Dapsone is initiated at a low dose (<0.5 mg/kg) and slowly increased until blistering and symptoms are controlled. The usual dose which controls the signs and symptoms of CBDC is 2 mg/kg. The dose, however, must be individualized, and dose finding to a level where patients may still have rare or occasional asymptomatic urticaria lesions is acceptable in patients with mild disease. Dose-related adverse effects include hemolysis, even without an underlying G6PD deficiency, and methemoglobinemia, which manifests as cyanosis, dyspnea, lethargy, and headache. A benign hemolysis is expected, and a compensatory reticulocytosis occurs [5, 7]. Idiosyncratic adverse reactions include agranulocytosis, peripheral neuropathy, hepatitis, gastrointestinal upset, cutaneous hypersensitivity reactions, and dapsone hypersensitivity syndrome. Initial laboratory evaluation should include a complete blood count (CBC) with differential, liver function tests, renal function tests including urinalysis, and a G6PD level test; a CBC should be performed frequently during the first 3 months of treatment, and interval blood work must be monitored thereafter [8]. Patients and their caregivers should be warned to present for urgent evaluation for fever, rash, or ill appearance.