What is childhood bullous pemphigoid?
Childhood bullous pemphigoid is a rare blistering disease affecting children under the age of 18. Unlike bullous pemphigoid in adults:
- The mucous membranes are much more commonly involved
- In infants younger than the 1 year of age, the palms and soles are often affected.
Childhood bullous pemphigoid has a favourable prognosis and results in minimal scarring.
What causes childhood bullous pemphigoid?
Childhood bullous pemphigoid is an autoimmune disorder. This means that an individual’s immune system starts reacting against his or her own tissue. In childhood bullous pemphigoid, autoantibodies react with components of the basement membrane (this membrane separates the epidermal and dermal layers of the skin), particularly the skin cell adhesion plate hemidesmosome-associated proteins BP180 and less frequently BP230. These proteins are within the non-collagenous (NC) 16A domain of collagen XVII.
In many patients with childhood bullous pemphigoid, skin antibodies can be detected in their blood stream. This is known as a positive indirect immunofluorescence test, because the antibodies are detected using fluorescence.
Clinical presentation of childhood bullous pemphigoid
The diagnosis of childhood bullous pemphigoid is based on the following features:
- Crops of large, tense, fluid-filled blisters (bullae)
- Blisters may be generalised on the skin
- In infants under 1 year of age, blisters tend to occur on hands and feet
- Blisters may be localised to mouth
- Blisters may be localised to vulva, particularly in later childhood
- Minimal scarring
Childhood bullous pemphigoid
How is the diagnosis of childhood bullous pemphigoid made?
In most cases the diagnosis of childhood bullous pemphigoid is made by a combination of typical clinical features and the results of biopsy of a blister.
Under the microscope, the pathologist can see a split between the outside layer of the skin, the epidermis, and the inside layer, the dermis – which means it is a subepidermal blister. See pathology of bullous pemphigoid.
Direct immunofluorescence staining highlights linear antibodies along the basement membrane of the skin biopsy.
What is the treatment for childhood bullous pemphigoid?
Treatment of childhood bullous pemphigoid is similar to that of adult bullous pemphigoid. The aim of treatment is to stop the formation of new blisters.
Ultra-potent topical steroids such as clobetasol propionate may be sufficient as a monotherapy, however many patients require systemic corticosteroids, with a starting dose of 1–2 mg/kg body weight each day of prednisone or prednisolone.
Other treatments that have been reported to be of benefit in childhood bullous pemphigoid are:
These are used either as monotherapy, or in combination with systemic corticosteroids.
In recalcitrant cases, the following medicines have been reported to be effective:
Overall, patients with childhood bullous pemphigoid have a favourable prognosis. The rash eventually clears up and treatment can be withdrawn.