Autoimmune Flashcards
What is Cutaneous Lupus Erythematosus (CLE)?
Cutaneous Lupus Erythematosus (CLE) is a diverse group of autoimmune connective tissue disorders localized to the skin, which can be associated with systemic lupus erythematosus (SLE) to varying degrees.
How is Cutaneous Lupus Erythematosus (CLE) classified?
Acute (ACLE)
Subacute (SCLE)
Intermittent (Lupus Tumidus)
Chronic (CCLE), which includes discoid lupus (DLE), lupus profundus, and chilblain lupus erythematosus.
What are the features of localized Acute Cutaneous Lupus Erythematosus (ACLE)?
Localized ACLE presents as a malar ‘butterfly’ rash, characterized by redness and swelling over both cheeks, sparing the nasolabial folds, and lasting hours to days.
What are the features of generalized Acute Cutaneous Lupus Erythematosus (ACLE)?
Generalized ACLE presents as diffuse or papular erythema of the face, upper limbs (sparing the knuckles), and trunk, resembling a morbilliform drug eruption or viral exanthem.
What is Toxic Epidermal Necrolysis-like Acute Cutaneous Lupus Erythematosus?
Toxic Epidermal Necrolysis-like ACLE is associated with lupus nephritis or cerebritis and must be distinguished from drug-induced toxic epidermal necrolysis in a patient with SLE.
Where do SCLE skin lesions typically occur, and what triggers them?
SCLE skin lesions typically occur on the trunk and upper limbs and are triggered or aggravated by sun exposure.
What are the common presentations of SCLE skin lesions?
SCLE presents as a psoriasiform papulosquamous rash or annular, polycyclic plaques with central clearing.
What is Intermittent Cutaneous Lupus Erythematosus?
Intermittent Cutaneous Lupus Erythematosus, better known as lupus tumidus, is a dermal form of lupus erythematosus.
Discoid Lupus Erythematosus (DLE): Prevalence in CCLE
DLE is the most common form of CCLE, accounting for 80% of cases, particularly prevalent and severe in patients with skin of color.
DLE: Lesion Characteristics
Presents as destructive scaly plaques with follicular prominence (carpet tack sign) which can result in scarring alopecia.
Dermatomyositis: Gottron’s Sign
Violaceous erythematous papules over knuckles, elbows, knees, and malleoli.
Dermatomyositis: Nailfold Signs
Telangiectasia and hemorrhage on the nailfold.
Dermatomyositis: Heliotrope Erythema
Violaceous erythema and swelling of the upper part of the face, with potential involvement of the whole face, neck, and upper chest.
Dermatomyositis: Organ Involvement
Involves the heart (~40%), smooth muscles, lungs, and rarely the kidneys and liver; calcinosis of fasciae may occur.
Dermatomyositis: Diagnostic Tests
Elevated creatine kinase, aldolase, MRI of affected muscles, and possibly muscle biopsy. Important to search for tumors, especially in adults (≈ 50% are paraneoplastic).
Dermatomyositis: Initial Therapy
Corticosteroids at 1-2 mg/kg body weight to start.
Dermatomyositis: Immunotherapy
Intravenous immunoglobulins (2 mg/kg body weight/month for up to a year), methotrexate (15-25 mg/week), and mycophenolate.
Dermatomyositis: General Management
Rest in the beginning, with careful and mild physiotherapy as tolerated.
Morphea: Lesion Characteristics
Asymmetric sclerotic plaques, usually 2–15 cm in diameter.
Morphea: Active Lesion Appearance
Active lesions may have a lilac border with central hypo- or dyspigmentation; older lesions often become hyperpigmented.
Morphea: Depth of Sclerosis
Sclerosis may extend deeply into fat or underlying structures such as fascia, muscle, and bone, potentially causing disability.
Pemphigus Vulgaris: Demographic Associations
More common in Europeans and Indians compared to Africans.
Pemphigus Foliaceus: Demographic Associations
More common in Africans compared to Europeans and Indians; associated with HLA B8 in South Africa.
Pemphigus Vulgaris: Affected Areas
Affects skin and mucous membranes. Always check the mouth
Pemphigus Vulgaris: Etiology
Caused by circulating IgG autoantibodies (90%) that bind to Desmoglein-3 (PV), a molecule involved in intercellular adhesion.
Desmoglein-1 vs. Desmoglein-3 in Pemphigus
Desmoglein-1 is more associated with Pemphigus Foliaceus, while Desmoglein-3 is linked to Pemphigus Vulgaris.
Pemphigus Foliaceus: Blister Visibility
Rarely visible blisters; often presents with more superficial erosions.
Pemphigus Foliaceus: Localization
Often localized rather than widespread.
Pemphigus Foliaceus: Oral Involvement
Oral involvement is very rare in Pemphigus Foliaceus
Bullous Pemphigoid: Age Group
Primarily affects the elderly.
Bullous Pemphigoid: Pathogenesis
Caused by IgG autoantibodies against BP230 and BP180 antigens, which are associated with hemidesmosomes.
Bullous Pemphigoid: Blister Formation
Inflammation leads to the formation of subepidermal bullae.
Bullous Pemphigoid: Initial Treatment
Managed with low-dose steroids, tapered within one week.
Chronic Bullous Disease of Childhood: Age of Onset
Usually occurs before the age of 5 years
Chronic Bullous Disease of Childhood: Affected Areas
Commonly affects the face and genital area.
Chronic Bullous Disease of Childhood: Blister Pattern
New blisters form around healing old blisters, creating a “string of pearls” appearance.
Chronic Bullous Disease of Childhood: Treatment Options
Treated with Dapsone or sulfapyridine; erythromycin or clarithromycin may also be used.
Dermatitis Herpetiformis: Primary Symptom
Characterized by itchy blisters on extensor surfaces.
Dermatitis Herpetiformis: Antibody Formation
Formation of IgA antibodies to gluten-tissue transglutaminase (t-TG) in the gut.
Dermatitis Herpetiformis: Genetic Predisposition
Linked to a genetic predisposition for gluten sensitivity
Dermatitis Herpetiformis: Cross-Reactivity
IgA antibodies cross-react with epidermal transglutaminase (e-TG), which is homologous to t-TG.
Dermatitis Herpetiformis: Pathogenesis
Deposition of IgA and epidermal TG complexes in the papillary dermis causes the lesions of dermatitis.
Epidermolysis Bullosa: Common Feature
Development of blisters following minor trauma or skin traction.
Epidermolysis Bullosa Simplex (EBS)
Blisters form within the basal layer of the epidermis due to defects in keratin filaments, typically following minor trauma.(keratin 5 & 14)
Junctional Epidermolysis Bullosa (JEB)
Blisters occur at the level of the lamina lucida within the basement membrane, often leading to severe and widespread blistering.
Dystrophic Epidermolysis Bullosa (DEB)
Blisters form below the basement membrane in the upper dermis due to mutations in the collagen VII gene, leading to scarring
EBS Weber-Cockayne: Affected Areas
Involvement of palms and soles; heat can exacerbate blistering and may lead to scarring.
EBS Dowling-Meara (Herpetiformis): Onset and Mortality
Onset just after birth; slight mortality rate associated
EBS Dowling-Meara: Blister Characteristics
Presents with herpetiform, hemorrhagic blisters on the trunk & Palmoplantar keratoderma, nail dystrophy, and mucosal erosions are common.
Junctional EB (Herlitz): Severity and Onset
Most severe subtype, often lethal; onset at birth.
Junctional EB (Herlitz): Clinical Features
Ulceration around the mouth, face, axilla, groin; oral blisters, dental anomalies, growth retardation.
Junctional EB (Herlitz): Complications
Esophageal ulceration leading to malnutrition, anemia, pain, and respiratory difficulties.
Junctional EB (Non-Herlitz): Clinical Features
Nail loss, scarring alopecia, modest mucosal involvement, and association with pyloric atresia.
Dominant Dystrophic EB: Onset and Presentation
Onset at birth; widespread blisters that heal with scars and milia, leading to mutilation of fingers and toes.
Dominant Dystrophic EB: Collagen Alteration
Caused by altered type VII collagen.
Recessive Dystrophic EB (Hallopeau-Siemens): Collagen Absence
Caused by the absence of type VII collagen.
Recessive Dystrophic EB (Hallopeau-Siemens): Onset and Severity
Onset at birth; similar to severe dominant dystrophic EB but with additional mucosal involvement, dental anomalies, scarring alopecia, anemia, and growth retardation.
Dystrophic EB: Complications
Pseudosyndactyly of the hands and feet, also known as “mittens and socks” deformity.
SCC
Epidermolysis Bullosa: General Treatment Approach
No cure for inherited EB; treatment focuses on managing clinical manifestations.
