What is Linear IGA Dermatosis?
Linear IgA bullous dermatosis (LABD) is a comparatively rare skin disease that causes blister-like sores. Both grown-ups and children can have this disease. In kids, we sometimes refer to it as “chronic bullous disease of childhood” because it looks a little different, but the cause is essentially the same.
When it comes to adults, one of the key things doctors must consider is whether a certain medication might have brought on LABD. This disease can also sometimes run in families. This genetic aspect partly explains why some children develop the chronic bullous disease of childhood or LABD. There are specific genes, known as human leukocyte antigen (HLA) types, that could increase a person’s likelihood of developing the disease. The most commonly linked HLAs are HLA-B8, HLA-DR3, HLA-DQ2, and HLA-cw7, and these are associated with the childhood and adult forms of LABD.
What Causes Linear IGA Dermatosis?
Linear IgA Bullous Dermatosis (LABD) is a skin condition that is primarily caused by a specific type of antibodies in your body called ‘IgA anti-basement membrane zone antibodies.’ These antibodies mistakenly attack a protein (BPAG2) found on a particular layer of your skin called the lamina lucida.
Sometimes, medications can cause these mistaken attacks and this is a common reason why adults get LABD. Of all the drugs that can cause LABD, the antibiotic vancomycin is the most frequent culprit, it is linked to almost half of the LABD cases caused by medications. Other antibiotics like penicillins, cephalosporins, and some types of sulfonamide antibiotics can also trigger the unwanted formation of these IgA antibodies, leading to LABD.
Apart from antibiotics, some other medications can cause LABD too. These include certain drugs used to control blood pressure (like captopril which is an angiotensin-converting enzyme inhibitor), non-steroidal anti-inflammatory drugs (like diclofenac and naproxen), and a medicine used for seizures called phenytoin.
There are also reports of some commonly used medications causing LABD. These include allopurinol, amiodarone, furosemide, atorvastatin, glyburide, angiotensin receptor blockers, verapamil, acetaminophen, and even the flu shot. Usually, if a medication is going to cause LABD, it typically happens within the first month of taking the drug.
Risk Factors and Frequency for Linear IGA Dermatosis
Linear IgA Bullous Dermatosis, or LABD, is a skin condition that can affect people of any age. The average age when symptoms begin to appear in adults often happens at two points in their life – during their teenage years or early adulthood and again in their sixties. In children, this condition often starts when they are around 4.5 years old, typically during their pre-school years. Each year, between 0.2 to 2.3 out of every million people are affected by this condition.
Signs and Symptoms of Linear IGA Dermatosis
Linear IgA bullous dermatosis (LABD) is an autoimmune skin condition that can be hard to distinguish from other similar diseases, such as bullous pemphigoid. People with this condition can have varied symptoms. For example, some may have blisters scattered across non-inflamed skin, while others might have redness beneath the blisters, giving them a more cluster-like appearance. These blisters often appear all over the body, typically on the trunk, extremities, scalp, genital area, or face. Some people may develop patches of blisters arranged in a ring, creating a “crown of jewels” or “string of pearls” effect. Children with this condition often have these circular lesions on their abdomen, lower back, thighs, groin area, or around their eyes and mouth.
It’s important to know that about half the people with LABD also have symptoms affecting their mucus membranes, such as the mouth, eyes, nostrils, and genital area. This can lead to significant scarring. The mouth and eye regions are the most often affected. Additionally, some LABD cases are caused by certain medications and tend to be far more severe.
LABD can manifest in different ways like resembling eczema, prurigo nodularis (itchy skin condition), hives, measles-like rash, even looking like seborrheic dermatitis. Despite the variability in symptoms, both adults and children with LABD can range from having no symptoms to experiencing mild or severe itching or burning sensations.
Testing for Linear IGA Dermatosis
If a doctor suspects that you have a skin condition called linear IgA bullous dermatosis (LABD), the most important step in confirming the diagnosis is to take samples (biopsies) of your skin for testing under a microscope. Two punch biopsies will typically be taken. A punch biopsy is a procedure to remove a small circle of tissue from your skin.
One of these samples is dyed with a stain called hematoxylin and eosin (H&E) so that the cells and tissues in the biopsy can be easily seen under the microscope. This sample is taken from an area of your skin where there’s a visible rash or lesion.
The other sample is tested using a technique called direct immunofluorescence (DIF), a method that uses fluorescent dyes to identify certain proteins or structures in the cells. This sample is taken from skin next to the rash or lesion.
Other tests may be performed to look for specific antibodies in your blood – these are proteins that your immune system produces when it responds to a harmful substance. About 70% of patients with LABD have specific antibodies against a part of the skin called the basement membrane zone, but patients with a different skin disorder, dermatitis herpetiformis (DH), do not have these antibodies. The test for this is called indirect immunofluorescence (IIF).
In one type of LABD, antibodies stick to the underside of the top layer of your skin when it’s separated in a salt solution, while in another variant of LABD, the antibodies stick to the top of the lower layer of skin.
Gathering a thorough history and performing a physical examination help the doctor make a likely diagnosis of LABD, sometimes even before the results of the biopsies return. It’s important for the doctor to know about all the medicines you’re taking, including over-the-counter ones, as well as any vitamins and supplements you’re using, since LABD can sometimes be triggered by a medication.
Treatment Options for Linear IGA Dermatosis
Linear IgA bullous dermatosis (LABD) is a skin disorder that has various treatment options since its discovery in the 1970s. The most common treatment is a medication called dapsone, which is usually taken orally. LABD responds exceptionally well to dapsone, with noticeable improvements occurring within two to three days of starting the medicine. As with any medication, it’s important for patients taking dapsone to continually be monitored for any potential side effects. These may include forms of anemia (a lack of enough healthy red blood cells), adverse reactions affecting white blood cells, liver problems, nerve issues, and a type of kidney disease known as nephrotic syndrome. Sometimes, oral corticosteroids may also be required for effectively managing the disease.
Another treatment option is the medication sulfapyridine. What’s interesting is that certain antibiotic treatments, like the tetracycline class, dicloxacillin, and trimethoprim-sulfamethoxazole have also been found to be effective. However, it’s still unclear why antibiotics, typically used for managing infections, can successfully control LABD as no connection with a specific infection has been found. If LABD is caused by a drug reaction, specifically to an antibiotic called vancomycin, changing the medication to another antibiotic like doxycycline can help not just control the infection but also potentially serve as a treatment for LABD. A supplement called nicotinamide might also serve as an additional or ‘adjunctive’ treatment.
What else can Linear IGA Dermatosis be?
: When a doctor is trying to diagnose Linear IgA Bullous Dermatosis (LABD), they go through a list of similar skin conditions to eliminate them. These include:
- Dermatitis herpetiformis
- Bullous pemphigoid
- Epidermolysis bullosa acquisita
- Bullous impetigo
- Pemphigus vulgaris
- Erythema multiforme
- Toxic epidermal necrolysis (TEN)
Dermatitis herpetiformis, for example, resembles LABD under certain diagnostic tests, the main difference being the pattern of IgA deposits. Bullous pemphigoid is defined by linear IgG deposits along a particular skin layer. Sometimes, though, both IgG and IgA deposits can be present, making the diagnosis more tricky. This can lead to debate about whether the condition is LABD or Bullous pemphigoid.
What to expect with Linear IGA Dermatosis
The outlook is generally good for both linear IgA bullous dermatosis (LABD), which is a skin condition caused by the immune system, and its pediatric version known as “chronic bullous disease of childhood”. For adults, the disease may spontaneously disappear in 30% to 60% of patients, typically after years with active symptoms.
In the case of children, the condition tends to spontaneously disappear on its own within 2 to 4 years of appearing, which offers reassurance to parents. Since medical treatments can sometimes hide the fact that a patient’s disease is healing on its own, it is often recommended to periodically stop these medications to check if the disease is naturally disappearing.
Additionally, LABD induced by medication also generally has a positive outlook. Most of such cases recover within 2 to 6 weeks once the patient stops taking the offending medication.
Possible Complications When Diagnosed with Linear IGA Dermatosis
Linear IgA bullous dermatosis (LABD) is a condition that tends to fluctuate in severity. If this condition is caused by a drug, it typically goes away on its own once the drug causing it is discontinued. Skin sores usually heal without leaving scars, however, sores that appear on inner body linings can leave scars and cause significant discomfort and health issues. Desquamative gingivitis, a type of LABD that affects gums, can harm teeth. Eye-related LABD may closely resemble a condition called cicatricial pemphigoid and may even lead to blindness.
Common Features and Complications:
- Fluctuating severity
- Automatically resolving in drug-induced cases upon discontinuing the drug
- Skin sores healing without scars
- Sores on inner body linings causing scars and potentially severe health issues
- Affects gums, possibly leading to damage to teeth
- Eye-related LABD potentially leading to blindness
Preventing Linear IGA Dermatosis
Patients diagnosed with a skin condition known as linear IgA bullous dermatosis (LABD) need to be carefully watched after starting treatment. If it’s discovered that a specific medication is causing this condition, it’s important to stop using that medication and not to use it ever again. It’s also crucial for patients to understand their condition and the importance of regular check-ups is emphasized.
