Pemphigus foliaceus

Pemphigus foliaceus

Pemphigus foliaceus is a chronic autoimmune blistering disease characterized by the formation of superficial, fragile blisters caused by autoantibody-mediated loss of adhesion between epidermal cells. Unlike pemphigus vulgaris, pemphigus foliaceus primarily affects the skin and rarely involves the mucous membranes because the autoantibodies mainly target desmoglein 1, a protein found in the superficial layers of the epidermis.

The disease is generally less severe than pemphigus vulgaris but may become widespread if untreated. Prompt diagnosis and immunosuppressive therapy help control disease activity and prevent complications.

Pathophysiology (Brief)

The main mechanism is autoimmune destruction of desmoglein 1, a protein responsible for adhesion between superficial epidermal cells.

This results in:

• Loss of cell-to-cell adhesion (acantholysis)

• Formation of superficial blisters

• Blisters that rupture easily, leaving crusted erosions

• Minimal or no mucosal involvement

Signs & Symptoms

Typical lesions include:

• Superficial flaccid vesicles and bullae

• Crusted erosions

• Scaly plaques

• Mild to moderate itching

• Burning sensation

Common sites:

• Face

• Scalp

• Chest

• Upper back

• Shoulders

Other findings:

• Lesions rupture easily before being noticed

• Widespread crusting

• Positive Nikolsky sign

• Mucosal involvement is uncommon

• Secondary bacterial infection may occur

Diagnostic Criteria

Diagnosis is based on:

• Superficial blistering and crusted erosions

• Absence of significant mucosal involvement

• Positive Nikolsky sign

• Histopathological findings

• Positive direct immunofluorescence

Investigations

Recommended investigations

• Skin biopsy

• Full blood picture (FBP)

• Liver function tests (LFTs)

• Renal function tests (RFTs)

Special investigations

• Direct immunofluorescence (gold standard)

• Indirect immunofluorescence where available

• ELISA for desmoglein 1 antibodies where available

Monitoring

During prolonged immunosuppressive therapy monitor:

• Full blood count

• Liver function

• Renal function

• Blood glucose in patients receiving corticosteroids

Treatment

Treatment aims to suppress autoimmune activity, heal skin lesions, prevent disease progression, and reduce the risk of relapse.

Non-pharmacological Treatment

• Maintain good skin hygiene.

• Protect affected skin from trauma.

• Use non-adherent dressings for eroded areas when necessary.

• Maintain adequate nutrition and hydration.

• Promptly treat secondary bacterial infection.

• Regular follow-up to monitor treatment response and adverse effects.

Pharmacological Treatment

• Betamethasone cream/ointment (topical) — apply every 12 hours until improvement.

OR

• Clobetasol propionate cream/ointment (topical) 0.05% — apply every 12 hours until improvement.

AND

• Prednisolone (PO) 0.5–1 mg/kg once daily for 2 months, then gradually taper to the lowest effective dose.

AND (for extensive involvement)

• Methotrexate (PO) 7.5–20 mg once weekly for not less than 4 months.

OR (steroid-sparing alternatives, specialist level):

• S: Methotrexate (PO) 10–15 mg once weekly for at least 4 months with folic acid.

• OR S: mycophenolate mofetil (PO) 1 g/day for at least 4 months.

• OR S: rituximab (IV) 375 mg/m² weekly for 4 weeks.

Additional treatment for pemphigus foliaceus

• Dapsone (PO) 100 mg once daily for not less than 2 months

Complications

• Secondary bacterial infection

• Widespread skin erosions

• Fluid loss in extensive disease

• Adverse effects of prolonged corticosteroid therapy

• Reduced quality of life

• Disease relapse

Prevention

There is no known method of preventing pemphigus foliaceus. However, complications can be minimized by:

• Early diagnosis

• Prompt initiation of treatment

• Regular clinical follow-up

• Appropriate wound care

• Early treatment of secondary infections

Patient counselling (Important)

• Pemphigus foliaceus is an autoimmune disease and is not contagious.

• The disease affects the skin but usually does not involve the mouth or other mucous membranes.

• Treatment may need to continue for several months.

• Do not discontinue corticosteroids or immunosuppressive medicines without medical advice.

• Keep affected skin clean and avoid unnecessary trauma.

• Report fever, increasing redness, pus, or worsening skin lesions promptly.