Pemphigus ICD-10: L10.9

Autoimmune blistering disease

Often searched as: blisters in mouth that won't heal, skin blisters that pop easily, sores inside mouth and skin, fragile blisters on body, raw skin from blisters, mouth ulcers that don't go away, autoimmune blisters, painful mouth and skin sores…

Clinical urgency level

lowmediumhigh

Systems Affected

skinmucous membranesmouthgenitalsesophagus (in some cases)

Severity Levels

mild

Limited blistering affecting a small skin or mucosal area, manageable with topical corticosteroids and low-dose systemic therapy.

moderate

Widespread blistering on skin and mucous membranes, significant pain and open wounds, requiring systemic immunosuppression.

severe

Extensive erosions covering large body surface area, risk of secondary infection, sepsis, or fluid loss; hospitalization may be needed. Paraneoplastic pemphigus (linked to malignancy) is the most severe variant.

Red Flags

  • Blisters or sores inside the mouth that persist more than 2 weeks
  • Widespread skin blistering appearing rapidly
  • Signs of infection in open skin wounds (fever, pus, spreading redness)
  • Difficulty eating, swallowing, or opening the mouth
  • Nikolsky sign positive (skin peels with light lateral pressure)
  • Blistering associated with a known cancer diagnosis (paraneoplastic pemphigus)

Clinical Presentation

Pemphigus vulgaris — flaccid blisters and erosions on the trunk

Pemphigus vulgaris — flaccid blisters and erosions on the trunk

Source: Wikimedia Commons (CC BY-SA 3.0 )

Pemphigus vulgaris oral erosions

View gallery on DermNet NZ (image gallery reference)

When to See a Doctor

See a dermatologist promptly if you develop painful, fragile blisters on the skin or inside the mouth that break easily and leave raw sores — especially if they are not healing. Mouth ulcers that last more than 2 weeks without explanation should always be evaluated. Pemphigus is serious and requires professional diagnosis and treatment.

Differential Diagnosis

  • Bullous pemphigoid (deeper blisters, more common in elderly)
  • Epidermolysis bullosa (genetic, not autoimmune)
  • Stevens-Johnson syndrome / TEN (drug reaction)
  • Mucous membrane pemphigoid
  • Aphthous stomatitis (mouth ulcers — less severe)
  • Herpes simplex (oral or genital blistering)
  • Dermatitis herpetiformis

Comorbidities

  • Thymoma or other malignancies (in paraneoplastic pemphigus)
  • Myasthenia gravis (associated with paraneoplastic variant)
  • Other autoimmune diseases (thyroid, rheumatoid arthritis)
  • Secondary bacterial infections
  • Corticosteroid side effects (diabetes, osteoporosis) from long-term treatment
  • Depression and anxiety

Prognosis

Before the era of corticosteroids, pemphigus vulgaris was often fatal. Today, with immunosuppressive therapy, most patients achieve remission. Rituximab has significantly improved outcomes in moderate-to-severe disease. However, relapses are common and long-term management is needed. Mortality is now mainly linked to treatment side effects or secondary infections rather than the disease itself. Paraneoplastic pemphigus carries a much worse prognosis.

Detailed Overview

Causes, Symptoms, and When to Take Action Pemphigus is a group of rare autoimmune skin diseases that cause blistering of the skin and mucous membranes. In pemphigus, the immune system mistakenly attacks proteins that help skin cells adhere to one another, leading to fragile blisters. How It Looks Texture: Flaccid, fragile blisters that easily rupture Color: Blisters appear on red or normal skin base; after rupture, may leave raw erosions Shape: Blisters may merge, leaving large areas of raw or crusted skin Location: Commonly involves mouth (mucous membranes), and skin on trunk, scalp, face, genitals Why Does It Appear? It's an autoimmune disorder: antibodies attack proteins (desmoglein 1 and 3) that hold skin cells together The loss of adhesion between skin cells causes fluid to accumulate and blisters to form Genetic predisposition and environmental triggers may contribute In rare cases, certain medications or cancers may trigger a pemphigus-like disease Should You Be Concerned? Yes. Pemphigus can cause: Painful mucosal and skin lesions that interfere with eating, swallowing, or daily life Risk of secondary infection in blistered areas Possible complications if not properly managed If you notice persistent, fragile blisters on skin or mucous membranes, especially in the mouth, seek evaluation by a dermatologist. Can You Prevent It? There is no known way to prevent pemphigus. Early recognition of symptoms and avoiding known triggers (e.g. certain medications) may help manage onset or flares. 👉 How Piel AI Can Help Piel AI can aid in tracking lesion appearance, size, spread, and healing over time using images. Though not diagnostic, this tracking can provide insight into disease progression and support timely discussion with a healthcare provider. Summary Pemphigus is an autoimmune blistering disease affecting skin and mucous surfaces. It causes fragile blisters and erosions due to loss of cell adhesion. The disease may lead to complications and requires professional care. Early detection, careful monitoring, and trigger awareness are important.

Tags

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