Authors: Esther Wang, Medical Student and Professor Dedee Murrell, Head, Department of Dermatology, St George Hospital, Sydney, Australia. A/Prof Amanda Oakley, Dermatologist, NZ 2018. Updated: Dr Musfira Shakeel, Salford Royal Foundation Trust, United Kingdom. Copy edited by Gus Mitchell. May 2022.
IgA pemphigus is very rare. It can occur in any age group, but is more commonly seen in middle aged adults and may have a female predominance.
What are the clinical features of IgA pemphigus?
The clinical features of IgA pemphigus include blisters, pustules, erythema, erosions and vegetating lesions.
The first signs are flaccidvesicles and pustules.
The vesicles and pustules rupture to form erosions and crustedplaques.
The eruption tends to follow an annular pattern.
IgA pemphigus appears to favour the trunk, upper and lower extremities, axillae, and groin. Mucosal involvement is infrequent.
IgA pemphigus
What is the cause of IgA pemphigus?
The exact cause of IgA pemphigus is unclear.
IgA autoantibodies bind to desmogleins or desmocollins, the cells responsible for adhesion between cells.
In SPD-type IgA pemphigus, the autoantigen is described as desmocollin 1, one of the desmosomal cadherins, the glycoproteins that maintain the shape of a cell.
In at least some cases of IEN-type IgA pemphigus, the autoantigens are desmoglein 1, desmoglein 3, and an unspecified transmembrane protein.
What is the differential diagnosis for IgA pemphigus?
Other conditions that should be considered in the differential diagnosis include:
In IgA pemphigus, a skin biopsy reveals intraepidermal neutrophilinfiltration. Blistering skin specimens will show mixed inflammatoryinfiltrate in upper, mid or lower epidermis, depending on the subtype with little or no acantholysis.
Direct immunofluorescence of a skin biopsy of healthy appearing skin close to the area of blistering reveals IgA deposition in epidermalkeratinocyte cell membranes.
Indirect immunofluorescence testing of serum can show IgA anti-keratinocyte cell-surface antibodies. Immunoglobulin G (IgG) anti-keratinocyte cell-surface antibodies have also been reported.
What is the treatment for IgA pemphigus?
IgA pemphigus is usually treated with a combination of systemic steroids (anti-inflammatory effects) and dapsone which is thought to reduce neutrophil infiltration. This combination treatment is more effective than the use of steroids alone.
Since few cases of IgA pemphigus have been described, the most effective treatment is unknown. Other medications worth considering include:
In comparison to other forms of pemphigus, IgA pemphigus presents with a milder disease and carries a better prognosis. When managed appropriately, it mostly heals with no scarring.
Patients should be counselled about potential side effects of steroids and dapsone. IgA associated with other medical conditions should be managed in a multidisciplinary manner, hence it is important to thoroughly investigate potential underlying triggers/associations, especially in elderly patients.
References
Aslanova M; Yarrarapu S.N.S; Zito. P.M. IgA pemphigus. Stat Pearls. Last updated 15th November 2021. Resource
Hashimoto T, Teye K, Ishii N. Clinical and immunological studies of 49 cases of various types of intercellular IgA dermatosis and 13 cases of classical subcorneal pustular dermatosis examined at Kurume University. Br J Dermatol 2016, 176: 168–75. DOI: 10.1111/bjd.14780. Journal
Ishii N, Ishida-Yamamoto A, Hashimoto T. Immunolocalisation of target autoantigens in IgA pemphigus. Clin Exp Dermatol 2004; 29: 62–6. PubMed
Liu YC, Tzung TY, Lin CB, Lo PY. IgA pemphigus: subcorneal pustular dermatosis type - A case report with vesicle and pustular eruption for 13 years cured with dapsone in 3 weeks. Dermatol Sinica 2008; 26: 258–63. Journal
Porro A, Caetano L, Maehara L, Enokihara M. Non-classical forms of pemphigus: pemphigus herpetiformis, IgA pemphigus, paraneoplastic pemphigus and IgG/IgA pemphigus. An Bras Dermatol 2014; 89: 96–106. DOI: 10.1590/abd1806-4841.20142459. Journal
Tsuruta D. Intercellular IgA dermatosis. Br J Dermatol 2017; 176: 13–14. Journal