Hailey-Hailey disease (HHD): Description, Causes and Risk Factors:
HDD is an autosomal dominant disorder characterized by outbreaks of rashes and blisters in the skin, usually in the folds of the skins, but also often over large areas of the body. The painful blisters break and sometimes become infected and raw, with new blisters forming over raw skin in a sometimes seemingly unending cycle of outbreaks.
The neck, axillae and the inguinal or perianal region are typically involved. Lesions show itchy patches with scaling crusts and fissured surfaces. They extend peripherally and the centre may heal or show soft, flat, moist vegetations.
It is caused by disturbed cell adhesion (acantholysis) in the upper layers of the epidermis. Researchers believe that the disease is due to defect in the calcium pump ATP2C1 gene which is located on chromosome 3q21-q24. This protein encoded by ATP2C1 is a calcium-transporting ATPase (Type 2C, member 1). Mutation of ATP2C1 result in haploinsufficiency for this intracellular, secretory pathway Ca2+/Mn2+ pump and lead to disturb the calcium homeostasis in the epidermis.
In affected individuals, reduced activity of this enzyme might cause instability of the desmosomes which results in loss of cohesion between keratinocytes (acantholysis), and development of vesicles. Mechanism by which mutant ATP2C1 causes acantholysis is unknown. The disease is more severe in summer. Flexural forms may become hypertrophic and malodorous. Mucosal involvement is rare, but oral, esophageal, vulvar and conjunctival involvement has been reported. Longitudinal white lines on the fingernails can be seen and fine palmer pits have also been documented. There are no extra-cutaneous manifestations and the general health is not impaired.
The initial lesion may be a red, scaly area or a fluid filled blister which ruptures easily and becomes macerated or crusted. These lesions seem to come and go and leave no scars. The lesions may be localized to an area or may become widespread. Patients with Hailey-Hailey disease may also have nail manifestation called `longitudinal leukonychia' which are longitudinal white bands on the fingernails.
Complications of Hailey-Hailey disease include risk of secondary bacterial
, fungal, and viral infections
, which may require antimicrobial agents.
It is very common for the condition to be mistaken for eczema (or dermatitis), a sweat rash, ringworm or impetigo (a bacterial skin infection).
Diagnosis is based on a combination of clinical and histological features. Typical features of HHD include vesicles on an erythematous base followed by erosions and crusting in intertriginous areas.
Skin biopsy typically reveals suprabasal acantholysis, causing the epidermal appearance of a dilapidated brick wall which is characteristic of HHD.
A negative direct immunofluorescence examination distinguishes HHD from pemphigus vulgaris. HHD causes acantholysis; however, as it is a genetic disease, autoantibodies are not involved.
There is no known cure for Hailey-Hailey disease since it is a genetic disorder. Treating patients for the symptoms does provide patients with relief and reduces the microbial infections.The first part of treatment is to avoid friction and sweating by wearing lightweight clothes. Avoiding direct sun and using sunscreen may also be helpful.
Corticosteroid creams are very helpful and these may be prescribed in a mix with an antibiotic to prevent skin infection. A pricking or itching sensation is usually present when a spot is starting and the corticosteroid cream may prevent the spot from developing any further if the cream is used as soon as you are aware of the itching sensation. The cream should be applied very thinly and only needs to be used once or twice a day on the affected skin. There is no need to put any cream on the unaffected skin.
Occasionally treatments which affect the immune system may be used (e.g. corticosteroids, ciclosporin, dapsone or methotrexate); these all, however, have potentially serious side effects so are only used in patients who do not respond to less severe treatment.
Topical photodynamic therapy, a type of light treatment, has been reported to help in some but not in other resistant cases. This involves the application of a cream that sensitises the cells to light, followed by exposure to a special red lamp 3 hours later. The treatment can be painful.
NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.