Pemphigoid nodularis

What is pemphigoid nodularis?

Pemphigoid nodularis is a rare nodular variant of bullous pemphigoid. There is limited literature on pemphigoid nodularis to date, with only case reports describing the condition. It was first described by Provost et al in 1979 and Yung et al in 1981.

Pemphigoid nodularis

Credit: Das D, Bandyopadhyay D. Juvenile pemphigoid nodularis: Report of a rare case. Indian Dermatol Online J 2014; 5: 189–92.

Who gets pemphigoid nodularis?

Pemphigoid nodularis is reported to be more common in women and elderly people.

What causes pemphigoid nodularis?

The causes of this nodular type of bullous pemphigoid are unknown. One theory is that the nodules are induced by rubbing and scratching in individuals with subclinical bullous pemphigoid.

Patients with prurigo nodularis (nodular prurigo) may induce pemphigoid antibodies through physical trauma to the skin and basement membrane.

What are the clinical features of pemphigoid nodularis?

Pemphigoid nodularis presents with hyperkeratotic nodules and blisters, which are usually located on the extremities and trunk.

The nodules are similar to those seen in nodular prurigo. Pruritic papules or confluent plaques have also been reported.

How is pemphigoid nodularis diagnosed?

Pemphigoid nodularis requires clinical or histological evidence of both pruritic nodules and blisters.

Histopathological features of pemphigoid nodularis include:

• Hyperkeratosis
• Spongiosis
• Subepidermal blisters
• Lymphocytes in the upper dermis.
• Positive direct immunofluorescence, with linear deposition of immunoglobulin (Ig)G and complement C3 along the basement membrane.

Blood tests may reveal positive indirect immunofluorescence and autoantibody titres to the 180-kD and 230- kD bullous pemphigoid antigens (BP180 and BP230).

What is the differential diagnosis for pemphigoid nodularis?

Pemphigoid nodularis can appear similar to nodular prurigo and other forms of prurigo. However, nodular prurigo lacks blisters and has no serum or immunofluorescence evidence of IgG to bullous pemphigoid antigens. Histology can be used to differentiate between the two conditions.

What is the treatment for pemphigoid nodularis?

The treatment for pemphigoid nodularis can be challenging. Topical steroid therapy alone is inadequate.

Pemphigoid nodularis is treated with the following:

• Systemic steroids, usually oral prednisone or prednisolone
• Doxycycline
• Methotrexate
• Azathioprine
• Cyclophosphamide.

What is the outcome for pemphigoid nodularis?

The prognosis of pemphigoid nodularis is uncertain. Older age and/or neurological comorbidities are associated with higher mortality rates.