The information on this website is not intended for diagnosis or treatment. Please consult your physician for health concerns.

+90 850 321 50 00

Linear IgA Dermatosis (LAD, Adult Form)

A subepidermal autoimmune blistering disorder defined by linear IgA deposition along the basement membrane zone, classically with annular vesiculobullous lesions in a string of pearls or cluster of jewels pattern; commonly drug-induced (vancomycin) in adults.

Written by: Saygı Hospital Health Guide Editorial Board
Last updated:

This content has been compiled by the Saygı Hospital Health Guide Editorial Board and is periodically reviewed by a specialist physician.

References (5)

This content is for informational purposes only and does not constitute medical advice. You can book an appointment at our Dermatoloji department. Book Appointment →

What is Linear IgA Dermatosis (LAD, Adult Form)?

Linear IgA dermatosis (LAD), formerly called linear IgA bullous dermatosis, is a rare autoimmune subepidermal blistering disease defined by the presence of linear IgA deposition along the basement membrane zone on direct immunofluorescence (DIF). It encompasses two forms: the chronic bullous disease of childhood (CBDC) and the adult-onset form. Annual incidence is 0.2–2.6 per million.

Adult LAD pathogenesis: autoantibodies (IgA1 subclass) target multiple basement membrane zone antigens including LAD285 (a cleaved 97 kDa fragment of BP180/collagen XVII), LAD-1, BP230, type VII collagen, p200/laminin γ1; antibody binding leads to subepidermal blister formation. The condition is most often drug-induced in adults — vancomycin accounts for over 50 percent of drug-induced cases (often within 1–15 days of starting therapy), other implicated drugs include captopril, lithium, phenytoin, NSAIDs, penicillins, ceftriaxone, amiodarone, furosemide, atorvastatin.

Clinical: skin lesions are tense vesicles and bullae on normal or erythematous skin, arranged in an annular or polycyclic pattern (pathognomonic 'string of pearls' or 'cluster of jewels' — peripheral vesicles around a central crust). Predilection sites: extensor surfaces, lower abdomen, perineum, thighs, buttocks; mucosal involvement (oral, ocular, nasal, esophageal, genital) occurs in 50–80 percent of idiopathic adult LAD and may cause scarring (similar to mucous membrane pemphigoid). Diagnosis: histology shows subepidermal blister with neutrophilic infiltrate (mimicking dermatitis herpetiformis); DIF is diagnostic with linear IgA at BMZ (vs granular IgA at dermal papillae in DH); indirect immunofluorescence on salt-split skin localizes to epidermal side (most common) or dermal side.

Symptoms

Tense vesicles and bullae on normal or erythematous skin
Annular or polycyclic arrangement (string of pearls / cluster of jewels — pathognomonic)
Pruritus, often intense and burning
Predilection for extensor surfaces, lower abdomen, perineum, thighs, buttocks
Oral mucosal involvement (50–80 percent in idiopathic adult LAD)
Ocular involvement: conjunctivitis, symblepharon, scarring (mucous membrane pemphigoid-like)
Esophageal, nasal, genital mucosal involvement
Recent initiation of vancomycin or other implicated drug (1–15 days prior)

Risk Factors

Recent vancomycin therapy (50 percent of drug-induced cases)
Captopril, lithium, phenytoin, NSAIDs, penicillins, ceftriaxone, amiodarone, furosemide, atorvastatin exposure
Older age (adult LAD peak in 60s)
Underlying lymphoproliferative disease (rarely paraneoplastic)
HLA-B8, HLA-DR3 (associated)
Inflammatory bowel disease (rare association)
No predilection by sex in adult form

When to See a Doctor?

If you experience any of the following symptoms, seek medical attention promptly:

  • New annular blistering rash in adult, especially after starting vancomycin
  • Tense bullae arising on normal or red skin
  • Oral, ocular, or genital mucosal blisters or erosions
  • Suspicion of immunobullous disease — same-day biopsy referral
  • Known LAD with new mucosal symptoms or progression
  • Vision changes with conjunctival blistering (urgent ophthalmology — risk of scarring)
  • Pre-treatment dapsone screening (G6PD, CBC, LFT) before starting therapy

Treatment Methods

01
Diagnostic: lesional and perilesional skin biopsy — H&E (subepidermal blister with neutrophilic infiltrate), direct immunofluorescence (linear IgA at BMZ — diagnostic), indirect IF on salt-split skin (epidermal vs dermal side localization), serum IgA antibodies to BP180/LAD285, BP230, type VII collagen if available
02
Discontinue all suspected medications immediately, especially vancomycin; document temporal relationship
03
First-line systemic: dapsone 25–50 mg daily, titrate to 100–200 mg daily based on response and tolerance; G6PD screening before initiation, baseline and weekly CBC for 2 months then monthly, LFT, methemoglobin level monitoring
04
Alternative if dapsone intolerance / contraindication: sulfapyridine 1–4 g daily, sulfasalazine, colchicine 0.6–1.2 mg daily
05
Topical: high-potency corticosteroids (clobetasol propionate 0.05 percent BID) for limited disease and adjunctive control
06
Oral corticosteroids (prednisone 0.5–1 mg/kg/day, taper as response) for severe or mucosal disease, especially with eye involvement
07
Steroid-sparing immunosuppressants for refractory or severe disease: mycophenolate mofetil 1–1.5 g BID, azathioprine, cyclosporine, IVIG, rituximab
08
Mucosal management: topical corticosteroid mouthwash (dexamethasone), tacrolimus ointment for oral lesions; ophthalmology consultation for any eye involvement (risk of cicatrizing conjunctivitis with vision loss)
09
Drug-induced LAD typically resolves within weeks to 2 months after discontinuation; idiopathic LAD often requires long-term therapy with relapses, may have spontaneous remission after years

Which Department to Visit?

You can visit our Dermatoloji department for these complaints. Our specialist physicians will create the most suitable treatment plan for you.

Learn About Dermatoloji Department

Let us help you

You can make an appointment with our specialists or contact us for your concerns.

Book AppointmentContact Us

Related Health Topics

Other articles from the same department you may want to explore.

Eczema (Atopic Dermatitis)

Dermatoloji

Atopic dermatitis is a chronic skin disease commonly seen especially in children, flaring with genetic predisposition and environmental triggers.

Psoriasis

Dermatoloji

Psoriasis is an autoimmune disease in which skin cells proliferate rapidly when the immune system mistakenly attacks the skin, leading to thick scaly lesions.

Acne

Dermatoloji

Acne is a skin disease resulting from clogging of hair follicles with oil and dead skin cells, commonly seen in adolescence but can occur at any age.

Rosacea

Dermatoloji

Rosacea is a chronic inflammatory facial skin disease characterized by recurrent flushing, persistent erythema, telangiectasia, and inflammatory papules and pustules. Phymatous change and ocular involvement may complicate advanced disease.

Urticaria (Hives)

Dermatoloji

Urticaria is a skin condition with sudden pink-red wheals and intense itching that may follow an acute or chronic course.

Skin Fungal Infections

Dermatoloji

Skin fungal infections are common, contagious skin diseases caused by dermatophytes and yeast fungi colonizing the upper layers of the skin.

Hair Loss (Alopecia)

Dermatoloji

Alopecia is a general term for hair loss that can be genetic, hormonal, autoimmune, or nutritional; early intervention can slow progression.

Vitiligo

Dermatoloji

Vitiligo is an acquired autoimmune disease in which CD8+ T cells destroy melanocytes, producing well-demarcated depigmented patches. Early, sustained treatment can induce repigmentation and prevent progression; psychosocial impact warrants holistic care.

Health Disclaimer: The information on this page is prepared for general informational purposes only. It does not replace medical diagnosis and treatment. Please consult your physician for your complaints. Saygı Hospital does not accept responsibility for actions taken based on the information on this page.