Hailey-Hailey disease

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Hailey-Hailey disease, also known as benign chronic pemphigus, is a rare skin condition that usually appears in early adulthood. The disorder is characterized by red, raw, and blistered areas of skin that occur most often in skin folds, such as the groin, armpits, neck, and under the breasts. These inflamed areas can become crusty or scaly and may itch and burn. The skin problems tend to worsen with exposure to moisture (such as sweat), friction, and hot weather.

The severity of Hailey-Hailey disease varies from relatively mild episodes of skin irritation to widespread, persistent areas of raw and blistered skin that interfere with daily activities. Affected skin may become infected with bacteria or fungi, leading to pain and odor. Although the condition is described as "benign" (noncancerous), in rare cases the skin lesions may develop into a form of skin cancer called squamous cell carcinoma.

Many affected individuals also have white lines running the length of their fingernails. These lines do not cause any problems, but they can be useful for diagnosing Hailey-Hailey disease.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Hailey-Hailey disease results from mutations in the ATP2C1 gene. This gene provides instructions for producing a protein called hSPCA1, which is found in many types of cells. The hSPCA1 protein helps cells store calcium until it is needed. Calcium has several critical functions in cells, including regulating cell growth and division (proliferation) and helping cells stick to one another (cell adhesion). The hSPCA1 protein appears to be particularly important for the normal function of cells called keratinocytes, which are found in the outer layer of the skin (the epidermis). In addition to proliferation and adhesion, calcium regulation in keratinocytes plays an important role in the barrier function of skin, which helps keep foreign invaders such as bacteria out of the body.

Mutations in the ATP2C1 gene reduce the amount of functional hSPCA1 protein in cells. This abnormality impairs cells' ability to store calcium normally. For unknown reasons, this abnormal calcium storage affects keratinocytes more than other types of cells. The abnormal regulation of calcium impairs many cell functions, including cell adhesion. As a result, keratinocytes do not stick tightly to one another, which causes the epidermis to become fragile and less resistant to minor trauma. Because the skin is easily damaged, it develops raw, blistered areas, particularly in skin folds where there is moisture and friction. In addition, abnormal calcium regulation disrupts the barrier function of the skin, making it more susceptible to infections. However, it is unclear how a reduction of hSPCA1 protein function affects the skin barrier, and how its impairment is involved in Hailey-Hailey disease.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Hailey-Hailey disease is a rare condition; its prevalence is unknown.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Acantholysis · Very frequent (99-80%)

The loss of intercellular connections, such as desmosomes, resulting in loss of cohesion between keratinocytes.

Erythema · Very frequent (99-80%)

Redness of the skin, caused by hyperemia of the capillaries in the lower layers of the skin.

Hyperkeratosis · Very frequent (99-80%)

Hyperkeratosis is a histopathological term defining a thickened stratum corneum and may be present in many different skin conditions, with many possible overlaps. Hyperkeratosis refers to the increased thickness of the stratum corneum, the outer layer of the skin. Hyperkeratosis is subclassified as orthokeratotic or parakeratotic. Orthokeratotic hyperkeratosis refers to the thickening of the keratin layer with preserved keratinocyte maturation, while parakeratotic hyperkeratosis shows retained nuclei as a sign of delayed maturation of keratinocytes.

Skin erosion · Very frequent (99-80%)

A discontinuity of the skin exhibiting incomplete loss of the epidermis, a lesion that is moist, circumscribed, and usually depressed.

Skin vesicle · Very frequent (99-80%)

A circumscribed, fluid-containing, epidermal elevation less than 10mm in diameter at the widest point that (i) Contain serous exudates or serum mixed with blood or pus; (ii) Are discrete, grouped, irregularly distributed, or linear as in Rhus dermatitis; (iii) Are short-lived. Vesicles may break spontaneously or evolve into bullae by enlarging or coalescing with other vesicles.

Which doctor should you see?

The suggested department for discussing Hailey-Hailey disease is Dermatology, with a dermatologist as the relevant type of clinician. Dermatologist; paediatric services for children as appropriate.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which features of the skin, hair or nails distinguish the possibilities?
• Would photographs over time help document the changes?
• What should be expected from treatment, and how will irritation or other adverse effects be managed?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Hailey-Hailey disease. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.