ConditionSkin, hair & nails
Linear IgA Disease (Linear IgA Bullous Dermatosis)
Linear IgA disease is a rare autoimmune skin condition in which IgA antibodies attack the layer that anchors the outer skin, causing itchy, tense blisters. In children (where it is called chronic bullous disease of childhood) blisters often form ring-like clusters around the genitals, lower belly and face. In adults it can appear on its own or be triggered by medicines, most often the antibiotic vancomycin. It is diagnosed with a skin biopsy and usually responds well to dapsone, and drug-induced cases clear after stopping the drug.
Also called: Linear IgA bullous dermatosis, LABD, linear IgA dermatosis, chronic bullous disease of childhood
At a glance
- What it is
- An autoimmune blistering disease caused by IgA antibodies against the skin's anchoring layer.
- Who gets it
- Children (usually preschool age) and adults, especially over 60.
- Triggers
- Often none. Vancomycin is the most common drug trigger, others include some NSAIDs and antibiotics.
- Diagnosis
- Skin biopsy with direct immunofluorescence showing a linear band of IgA.
- Treatment
- Stop any trigger drug, dapsone, steroid creams, and other medicines if needed.
When to get help
Call 911 or go to the ER
- Widespread blistering with skin peeling, fever, and sores in the mouth, eyes or genitals (possible severe drug reaction such as Stevens-Johnson syndrome)
See a doctor within a day or two
- New blistering rash during or after a course of vancomycin or another new medicine
- Blisters with eye redness, grittiness or pain (eye involvement can scar)
- Painful mouth sores making it hard to eat or drink
- Blisters that are oozing pus, crusting yellow, or with fever above 38 °C (100.4 °F)
Book a routine appointment
- Itchy blisters in clusters or rings that keep appearing over weeks
- A child with a recurring blistering rash around the groin or face
What happens in linear IgA disease
The outer skin (epidermis) is attached to the deeper skin (dermis) by the basement membrane zone, held together by anchoring proteins. In linear IgA disease, the immune system makes IgA antibodies against parts of these proteins (often fragments of collagen XVII, the same protein targeted in bullous pemphigoid). The antibodies trigger inflammation that separates the layers, forming blisters.
Symptoms
In children
- sudden onset of tense, fluid-filled blisters on normal or red skin
- blisters arranged in rings or rosettes, with new blisters at the edges, often described as a "string of pearls" or "cluster of jewels"
- usually on the lower belly, groin, genitals, thighs and face
- itching or burning
- sometimes mouth sores
In adults
- itchy blisters and red, raised patches, often on the trunk and limbs
- patterns that can resemble bullous pemphigoid or dermatitis herpetiformis
- mouth, eye, nose or genital involvement in some people
Drug-induced linear IgA disease
- usually starts within a few days to a few weeks of starting a medicine
- vancomycin is the most common cause. Others include some NSAIDs, penicillins, cephalosporins, captopril and lithium
- can be more extensive and sometimes resembles toxic epidermal necrolysis
- typically clears within weeks of stopping the drug
Eye involvement
Some people develop red, gritty eyes. Over time, mucous membrane inflammation can cause scarring of the eye surface, which can affect vision. Anyone with eye symptoms needs an eye specialist.
Causes and associations
Most cases have no identifiable trigger. Associations include:
- medicines, as above
- infections preceding the rash in some children
- inflammatory bowel disease, especially ulcerative colitis
- rarely, some cancers such as lymphoma
Unlike dermatitis herpetiformis, linear IgA disease is not usually linked to celiac disease.
Similar blistering conditions
| Condition | Key differences |
|---|---|
| Bullous pemphigoid | Older adults, IgG antibodies, large tense blisters |
| Dermatitis herpetiformis | Small, intensely itchy blisters on elbows, knees and buttocks, linked to celiac disease, granular IgA deposits |
| Pemphigus vulgaris | Fragile blisters that burst easily, painful mouth sores |
| Bullous impetigo | Bacterial infection, honey-colored crusts |
| Erythema multiforme or SJS | Target lesions, mucosal involvement, often drug or infection-related |
Diagnosis
- Skin biopsy from the edge of a new blister, for routine examination under the microscope
- Direct immunofluorescence of a biopsy taken from normal-looking skin next to a blister: shows a characteristic linear band of IgA along the basement membrane, the key test
- Blood tests for circulating IgA antibodies in some cases
- Glucose-6-phosphate dehydrogenase (G6PD) level before starting dapsone
- Eye examination if eyes are affected
Treatment
- Stop the trigger medicine in drug-induced cases. The rash usually clears within 2 to 6 weeks.
- Dapsone is the first-line medicine and often works within days. It requires regular blood tests to watch for anemia and other side effects, and G6PD testing beforehand.
- Sulfapyridine or sulfamethoxypyridazine as alternatives.
- Potent topical steroids for mild disease or alongside tablets.
- Oral steroids for more severe disease.
- Other options for resistant cases: antibiotics with anti-inflammatory effects (such as erythromycin or tetracyclines with nicotinamide), mycophenolate, IV immunoglobulin, or rituximab.
- Wound care: keep blisters clean, drain large tense blisters with a sterile needle while leaving the roof in place, and use non-stick dressings.
Outlook
Childhood linear IgA disease usually goes into remission within a few years, often before puberty. Adult disease is more variable and may last longer, with flares and remissions. Drug-induced disease generally resolves completely once the medicine is stopped, and the drug should be avoided in future. Eye involvement needs long-term monitoring to prevent scarring.
Frequently asked questions
What is linear IgA disease?
It is a rare autoimmune condition where IgA antibodies attack the layer joining the outer and deeper skin, causing itchy blisters. It affects children and adults and is named for the linear band of IgA seen on a special skin biopsy test.
What does linear IgA disease look like?
It causes tense, fluid-filled blisters, often arranged in rings or clusters with new blisters around the edge, sometimes called a "string of pearls". In children it often affects the groin, lower belly and face. Adults may have more scattered blisters.
Can vancomycin cause linear IgA disease?
Yes. Vancomycin is the most common medicine linked to linear IgA disease. The rash usually appears within days to weeks of starting the drug and clears after it is stopped. Future vancomycin should be avoided.
How is linear IgA disease treated?
Stopping any trigger medicine is the first step. Dapsone is the main treatment and usually works quickly. Steroid creams or tablets and other immune-modulating medicines are used for more severe or resistant cases.
Does linear IgA disease go away?
Often, yes. Childhood cases usually resolve within a few years. Drug-induced cases clear after stopping the drug. Adult cases may last longer with periods of remission, but most are well controlled with treatment.
Sources
This guide was written from current patient and clinical guidance, including:
- DermNet: Linear IgA bullous dermatosis
- National Organization for Rare Disorders (NORD): Linear IgA dermatosis
- American Academy of Dermatology: Blistering diseases
- MedlinePlus Genetics and NIH Genetic and Rare Diseases Information Center: Linear IgA dermatosis
- British Association of Dermatologists: Patient information on immunobullous diseases