Linear IgA dermatosis
Last Updated: 2023-09-28
Author(s): Navarini A.A.
ICD11: EB42
Last Updated: 2023-09-28
Author(s): Navarini A.A.
ICD11: EB42
Linear IgA dermatosis is a rare, chronic autoimmunological skin disease that leads to the formation of blisters. It is characterised by linear deposits of IgA and C3 at the border zone between dermis and epidermis. It can occur in adults due to various causes. It is known in children as benign chronic bullous dermatosis
It can occur in childhood as well as in adulthood. In children, the disease often occurs at preschool age and has a favourable prognosis with spontaneous remission in the majority of cases. In adults, the disease is usually more severe and requires long-term therapy. Linear IgA dermatosis occurs with varying frequency in different ethnic groups. There are reports of higher prevalence in China and parts of Africa.
Chorzelski u. Jablonska
The disease is rare, with an incidence of approximately 0.02-0.05 per 100,000 inhabitants per year in Germany and France. In larger groups of patients with blistering disease, linear IgA dermatosis accounts for less than 1%. In certain regions, such as China and parts of Africa, the disease appears to be more common. In children, it represents the most common blistering autoimmune disease.
Two main forms of the disease differ in their aetiology:
The skin changes are manifested by itchy, urticarial plaques that may have vesicular or bullous lesions. About half of the patients also have mucosal changes. It is not uncommon to find rosette-like bullae.
Histological examinations can be supportive but are not diagnostically specific. Direct immunofluorescence reveals linear IgA deposits at the dermoepidermal junction zone.
Often the skin changes manifest in the area of the face, especially around the mouth and near the ears, and on the upper body. Arms and legs, including the upper and inner surfaces of the hands, can also be affected.
In children, the disease usually appears between the ages of 2 and 4. In adults, on the other hand, it often appears between the ages of 20 and 40 or only after the age of 60.
Histology shows subepidermal blistering with an infiltrate of lymphocytes and neutrophil granulocytes. Two types can be distinguished by immunoelectron microscopy.
Possible complications include ulcerative colitis, Crohn's disease, dermatomyositis, various malignancies and, if the conjunctiva are involved, scarring to the point of blindness.
The idiopathic form of LAD can last for years.
Specific preventive measures are not known. However, they should be avoided in the case of known drug intolerance.
Therapy depends on the severity of the disease. Commonly used medications include dapsone and systemic corticosteroids. In mild disease, topical steroids may be sufficient. In severe forms or in patients who do not respond to first-line therapy, immunosuppressants such as methotrexate or cyclophosphamide may be required.
