Linear IgA dermatosis is an autoimmunologic disease of the skin in which the body’s immune system produces autoantibodies against adhesion proteins. The result is blistering and reddening of the skin, which in individual cases may also affect the eye. If the eyes are involved, there is a risk of blindness, which may require invasive treatment procedures in addition to drug therapies.
What is linear IgA dermatosis?
The immune system serves to recognize and defend against substances foreign to the body as well as pathogens. In autoimmune diseases, on the other hand, the defense system directs antibodies against the body’s own tissues. In principle, autoimmune diseases can attack any type of tissue. If the skin tissue is the target of the autoimmune antibodies, we speak of autoimmune dermatoses. One such dermatosis of autoimmunologic origin is linear IgA dermatosis, also referred to by the medical literature as IgA pemphigoid or chronic bullous dermatosis of childhood. The disease is associated with erythema and blistering. It is an extremely rare disease that predominantly affects women and younger children. Among autoimmune dermatoses, the disease can be assigned to the subcategory of blistering autoimmune dermatoses because of the associated blistering. The primary cause of linear IgA dermatosis can only be speculated to date. The annual incidence of the disease is less than one case per 100 000 inhabitants in Germany.
Causes
Although the primary causative factors for autoimmune diseases remain the subject of speculation to this day, at least the pathophysiology can be largely explained. Linear autoimmunologic IgA dermatosis represents a misprogramming of the immune system that results from unexplained genesis. Based on the misprogramming, the body’s own defense system forms autoantibodies in the serum. These autoantibodies are directed against a protein in the intracellular plaques of hemidesmosomes. Hemidesmosomes are adhesive complexes that firmly attach epithelial cells to the underlying basement membrane. With the destruction of important proteins in the intracellular plaques of the adhesion complexes, adhesion is lost. Along the basement membrane, antigen-antibody complexes form at the same time, activating the complement cascade. This activation results in the characteristic erythema of linear IgA dermatosis. Scientists now suggest that the misprogramming of the defense system in this case may be induced by drugs, for example.
Symptoms, complaints, and signs
Patients with linear IgA dermatosis characteristically suffer from manifold blisters of the external skin. In most cases, the blisters do not develop on healthy skin, for example, but form on severely reddened areas of skin in the sense of erythema. In some cases, erythema and blisters coexist. In other cases, blisters replace erythema and vice versa. The occurrence of blistering on mucous membranes is not completely excluded, but rather not characteristic. The patients’ skin lesions are usually accompanied by more or less severe itching, burning sensations or pain. Many patients scratch the blisters to relieve the itching. However, this approach can make the lesions worse. Most commonly, the skin lesions occur on the proximal extremities or around the trunk. Eye involvement has been documented in isolated cases. This ocular involvement can lead to blindness or result in the formation of entropion because of the scar tissue that develops.
Diagnosis and course of the disease
Diagnosis of linear IgA dermatosis is typically based on immunohistopathology. The autoantibodies must be isolated from the skin to make the diagnosis and to confirm an existing suspicion of autoimmune dermatosis. The first suspicion usually comes to the dermatologist by visual diagnosis. To confirm the diagnosis, he secures the linear IgA and complement deposits on the basement membrane. In some cases, the specific autoantibodies can even be detected in the patient’s serum. Therefore, laboratory diagnostic detection may also be considered. However, the disease is by no means excluded if the specific antibodies are not detectable in the serum.Differentially, linear IgA dermatosis must be distinguished from skin diseases such as dermatitis herpetiformis Duhring or bullous pemphigoid. For patients with IgA dermatosis, the prognosis cannot be generalized. Typically, autoimmune diseases are characterized by individual courses.
Complications
In this disease, affected individuals primarily suffer from vesicles on the skin. These can lead to decreased aesthetics and thus significantly reduce the patient’s quality of life. Inferiority complexes and reduced self-esteem occur. It is not uncommon for those affected to also develop depression or other psychological upsets. Furthermore, the disease also causes itching or burning pain on the skin. If these pains also occur at night, the patient may have trouble sleeping and become irritable. Complications usually occur when the disease also affects the eyes. In the worst case, the affected person can go blind. Due to the permanent pain and discomfort on the skin, there are severe limitations in the patient’s life. In most cases, the disease is treated with the help of medication and leads to success. However, it is not uncommon for patients to require prolonged treatment. Even after treatment, the disease may develop again. The life expectancy of the patient is usually not affected.
When should you go to the doctor?
Anyone who notices blisters, redness, and other skin changes should seek medical advice promptly. Although linear IgA dermatosis occurs very rarely, it can have serious health implications if treated too late or not at all. Affected individuals should therefore have even inconspicuous skin lesions examined by a physician. If pain, itching or crusting are added, it is best to see a doctor the same day. Mucous membrane adhesions around the eyes must be treated immediately. Otherwise, severe pain and visual disturbances may occur. Linear IgA dermatosis occurs predominantly in children. Risk factors are infections or tumor diseases. The disease often occurs in conjunction with a chronic inflammatory bowel disease such as Crohn’s disease. Affected individuals should consult their family physician or a dermatologist. Any visual disturbances must be presented to the ophthalmologist. If psychological problems develop as a result of the skin changes, a trusted person should be spoken to. In case of doubt, it is recommended to talk to a psychologist.
Treatment and therapy
Patients with IgA dermatosis receive a combination of external and internal therapy. External therapy includes anti-inflammatory treatment, which may include synthetic tanning agents. Internal therapy is with agents such as DADPS. Depending on the current situation and the course in the individual case, the drugs and their dosage are adjusted bit by bit. Azathioprine and systemic corticosteroids may be considered if the situation remains unchanged. In addition, cyclophosphamide, colchicine as well as mycophenolate mofetil, methotrexate and ciclosporin A are internal therapy options. In general, linear IgA dermatosis responds well to immunosuppressants as well as sulfones and sulfapyridines. Immunosuppression dampens the entire immune system and thus also reduces the formation of autoantibodies. All immunosuppression measures can be used in the form of long-term therapy. For acute therapy, other agents are usually more suitable. Systemic treatment of itching can be achieved by systemic administration of various antihistamines. Unlike many other autoimmune dermatoses, dietary measures are largely ineffective in autoimmune IgA-linear dermatosis. In the case of ocular involvement, invasive measures may be required. Especially after the formation of entropion, ophthalmologic correction is needed.
Outlook and prognosis
When medical care is sought, the prognosis of linear IgA dermatosis is favorable. The immune system defect can be well regulated by administration of drugs with current medical options. If left untreated, the symptoms persist continuously or increase in intensity or severity.In addition, psychological sequelae are to be expected, and many of those affected experience severe emotional stress due to the visual conspicuities. The earlier a diagnosis is made, the sooner treatment measures are possible and relief can be seen. Despite the good therapy options, side effects may occur due to the prescribed preparations. These have a delayed effect on the healing process, since a restructuring of the treatment plan is necessary. Although the disease can be treated well with the available medications, long-term treatment is necessary in most cases. The disease recurs immediately upon discontinuation of medication in most patients. For this reason, those affected have to undergo medical treatment for several months or years. This circumstance can also have a negative effect on the psyche of the affected person. Depending on the personality of the patient, possible psychological secondary disorders develop. If the course of the disease is unfavorable, the affected person may go blind. In these patients, the prognosis is considerably worse.
Prevention
The primary triggers of malprogramming of the body’s immune system remain a matter of debate to this day. If, as speculation suggests, different drugs do indeed trigger IgA dermatosis, these drugs could be avoided as a preventive step. On the other hand, promising alternatives are not available for all drugs.
Follow-up
In skin diseases, the measures of a follow-up usually depend very much on the exact disease, so that no general prediction can usually be made in this regard. However, IgA dermatosis must also be examined and treated by a physician in the first instance to prevent further complications or discomfort. The earlier this disease is detected and treated by a physician, the better the further course will be. For this reason, it is advisable for those affected to see a doctor at the first symptoms and signs. A high standard of hygiene also has a positive effect on the course of such diseases in most cases. In most cases, these diseases are treated by applying creams or ointments and by taking medications. Affected persons should pay attention to regular use and also to the correct dosage in order to permanently alleviate complaints. Regular checks by a doctor are very important. In most cases, skin diseases do not have a negative effect on the life expectancy of the affected person. Contact with other patients can also be useful in this regard.
What you can do yourself
It is not possible to treat Linear IgA Dermatosis by self-help means. Affected individuals are therefore always dependent on medical treatment to prevent further complications and discomfort. First and foremost, early diagnosis and treatment are therefore necessary, as these always increase the chance of a positive course of the disease. Therefore, if the first symptoms of Linear IgA Dermatosis appear, a doctor should be consulted immediately. Since the treatment of Linear IgA Dermatosis is mainly carried out with the help of medications, affected persons should always pay attention to a correct dosage and to a regular intake. Interactions with other medications should also not be ignored. If blindness has occurred, the patient is dependent on help in his or her everyday life. Ideally, this help should come from relatives or friends and relieve the patient in his daily life. Often, empathetic conversations with the closest friends or with other trusted persons can prevent and alleviate psychological complaints. The same applies to psychological discomfort due to the reduced aesthetics caused by the skin complaints.