Autoimmune Skin Diseases

Autoimmune Skin Diseases Indian Medical PG Question 1: A 45-year-old man presents with the following skin changes (as shown in the image). What relevant history should be taken to diagnose this condition?

• A. Dementia
• B. History of dietary pattern, dementia, and diarrhea (Correct Answer)
• C. Dietary history
• D. Depression

Autoimmune Skin Diseases Explanation: ***History of dietary pattern, dementia, and diarrhea*** - The image displays skin changes consistent with a "Casal's necklace" pattern, characteristic of **pellagra**, a disease caused by **niacin (Vitamin B3) deficiency**. - Pellagra is classically associated with the "3 Ds": **dermatitis** (the observed skin changes), **diarrhea**, and **dementia**. A comprehensive history should therefore include questions about dietary patterns (especially corn-based diets lacking tryptophan and niacin), gastrointestinal symptoms like diarrhea, and neurological/psychiatric symptoms indicative of dementia. *Dementia* - While **dementia** is one of the classic "3 Ds" of pellagra (niacin deficiency), it is only one component of the presentation and insufficient on its own to guide a complete diagnostic history for this condition. - Focusing solely on dementia would miss crucial aspects like dietary intake and gastrointestinal symptoms that are integral to diagnosing pellagra. *Dietary history* - A **dietary history** is indeed very relevant for diagnosing pellagra, as it helps identify potential niacin deficiency, commonly associated with diets heavily reliant on corn without proper preparation. - However, pellagra is not only characterized by dermatological signs and dietary insufficiency but also by gastrointestinal and neurological symptoms. Limiting the history to diet alone would therefore be incomplete. *Depression* - **Depression** can be a symptom of various nutritional deficiencies and other medical conditions, but it is not one of the classic "3 Ds" of pellagra, which are dermatitis, diarrhea, and dementia. - While mood changes might be present in some patients with niacin deficiency, focusing solely on depression would not encompass the full clinical picture of pellagra and could lead to misdiagnosis.

Autoimmune Skin Diseases Indian Medical PG Question 2: What is the screening test for scleroderma?

• A. Anti-nuclear antibody (Correct Answer)
• B. U1-Ribonucleoprotein antibody
• C. Anti-LKM antibody
• D. Anti-topoisomerase antibody

Autoimmune Skin Diseases Explanation: ***Anti-nuclear antibody*** - **ANA** is the most sensitive **screening test** for systemic autoimmune diseases, including scleroderma [1]. - A positive ANA test indicates the presence of autoantibodies, leading to further, more specific testing for scleroderma. *U1-Ribonucleoprotein antibody* - This antibody is primarily associated with **mixed connective tissue disease (MCTD)**, not scleroderma as a screening test [1]. - It can be positive in other autoimmune diseases, but it is not the primary screening test for scleroderma. *Anti-LKM antibody* - **Anti-liver kidney microsomal (LKM) antibody** is predominantly found in **autoimmune hepatitis type 2**. - It has no role in the screening or diagnosis of scleroderma. *Anti-topoisomerase antibody* - This antibody, also known as **anti-Scl-70**, is **highly specific for diffuse systemic sclerosis** (scleroderma). - While specific, it is used as a confirmatory test once scleroderma is suspected, rather than a general screening test.

Autoimmune Skin Diseases Indian Medical PG Question 3: A 60-year-old female presents with eczematous itching lesions. Biopsy revealed a subepidermal cleft with Direct Immunofluorescence showing Linear C3 & IgG deposition along the basement membrane zone. What is the likely diagnosis?

• A. Pemphigus foliaceus
• B. Pemphigus Vulgaris
• C. Dermatitis herpetiformis
• D. Bullous Pemphigoid (Correct Answer)

Autoimmune Skin Diseases Explanation: ***Bullous Pemphigoid*** - The presence of **eczematous itching lesions**, a **subepidermal cleft**, and **linear C3 and IgG deposition along the basement membrane zone** on direct immunofluorescence (DIF) are classic diagnostic features of Bullous Pemphigoid. - This autoimmune blistering disease typically affects older individuals and is characterized by antibodies targeting components of the **hemidesmosomes**, specifically BP180 and BP230. *Pemphigus foliaceus* - This condition involves **intraepidermal blistering**, specifically within the granular layer, rather than a subepidermal cleft. - DIF in Pemphigus foliaceus shows **intercellular IgG deposition** in the epidermis, not linear deposition along the basement membrane zone. *Pemphigus Vulgaris* - Pemphigus Vulgaris is characterized by **intraepidermal blistering** above the basal cell layer (**suprabasal clefting**), leading to fragile bullae that rupture easily. - DIF typically reveals **intercellular IgG and C3 deposition** in a "chicken wire" pattern throughout the epidermis, which differs from the linear pattern seen in this case. *Dermatitis herpetiformis* - While Dermatitis herpetiformis is also an autoimmune blistering disease with itching lesions, its characteristic DIF finding is **granular IgA deposition** in the dermal papillae, not linear C3 and IgG at the basement membrane zone. - Histopathology in Dermatitis herpetiformis shows **subepidermal vesicles** with neutrophil infiltration in the dermal papillae, but the direct immunofluorescence pattern is distinct.

Autoimmune Skin Diseases Indian Medical PG Question 4: Steroids are used in the Rx of the following diseases EXCEPT:

• A. Pemphigus vulgaris
• B. Chronic fungal infection (Correct Answer)
• C. Erythema multiforme
• D. Contact dermatitis

Autoimmune Skin Diseases Explanation: ***Chronic fungal infection*** - **Steroids are absolutely contraindicated** in **chronic fungal infections** as they **suppress cell-mediated immunity**, leading to worsening of the infection and potential dissemination. - Corticosteroids promote fungal growth and can convert a localized infection into a systemic, life-threatening condition. - This is the **clearest contraindication** among the options. *Pemphigus vulgaris* - **Pemphigus vulgaris** is an **autoimmune blistering disease** where **high-dose systemic steroids are the first-line treatment**. - Corticosteroids (1-2 mg/kg/day of prednisolone) are essential for controlling autoantibody production and preventing life-threatening complications. - **Steroids are clearly indicated**, not contraindicated. *Erythema multiforme* - **Erythema multiforme** is typically a **self-limiting condition** managed primarily with **supportive care** (antipyretics, antihistamines, topical care). - **Systemic steroids are generally NOT recommended** as standard treatment and their use remains **controversial**. - However, in very rare severe cases with extensive mucosal involvement, some clinicians may consider a short course, making this **not an absolute contraindication** like fungal infections. *Contact dermatitis* - **Contact dermatitis** is commonly treated with **topical corticosteroids** as first-line therapy to reduce inflammation and pruritus. - In severe, widespread cases, a short course of **oral steroids** may be prescribed. - **Steroids are clearly indicated** for this condition.

Autoimmune Skin Diseases Indian Medical PG Question 5: A 35-year-old woman consulted a dermatologist due to a persistent facial rash. Physical examination revealed an erythematous rash, without blistering or ulceration, involving both cheeks and the nose, with the nasolabial folds relatively spared. The dermatologist also noted scattered erythematous, firm, maculopapular lesions on the face, neck, upper chest, and elbows, as well as focal alopecia on the scalp. The patient reported that the rash had been present for approximately six months, with exacerbation upon exposure to sunlight. Which autoimmune disease would MOST likely produce this patient's skin problems?

• A. Dermatomyositis
• B. Progressive systemic sclerosis
• C. Systemic lupus erythematosus (Correct Answer)
• D. Rheumatoid arthritis

Autoimmune Skin Diseases Explanation: ***Systemic lupus erythematosus*** - The **malar rash** (sparing the nasolabial folds) and photosensitivity are classic dermatological findings in **systemic lupus erythematosus (SLE)**. - **Focal alopecia** and other **maculopapular lesions** are also characteristic skin manifestations of SLE. *Dermatomyositis* - While dermatomyositis can also present with photosensitive rashes, the typical facial involvement includes **heliotrope rash** around the eyes or **Gottron's papules** over bony prominences. - The description of a malar rash sparing nasal folds and scattered maculopapular lesions is less consistent with dermatomyositis. *Progressive systemic sclerosis* - This condition is primarily characterized by **skin thickening and hardening** (scleroderma), often starting in the extremities and face. - The described **erythematous rash** with separate maculopapular lesions and alopecia is not typical for progressive systemic sclerosis. *Rheumatoid arthritis* - Rheumatoid arthritis is a chronic inflammatory joint disease and does **not typically present with primary dermatological manifestations** like the facial rash, photosensitivity, or alopecia described. - While some skin findings can occur (e.g., rheumatoid nodules), they are not the prominent features described.

Autoimmune Skin Diseases Flashcard 1 of 5

Question: _____ Lupus Erythematosus presents most commonly as a non scarring papulosquamous eruptions in 2/3rd cases

Answer: Subacute Cutaneous

Autoimmune Skin Diseases Flashcard 2 of 5

Question: _____ is an autoimmune inactivation of desmosomes between keratinocytes

Answer: Pemphigus vulgaris

Autoimmune Skin Diseases Flashcard 3 of 5

Question: IPEX syndrome is associated with a variety of dermatological findings, but in particular patients present with dermatitis, nail _____, and other autoimmune dermatologic conditions (especially autoimmune alopecia)

Answer: dystrophy

Autoimmune Skin Diseases Flashcard 4 of 5

Question: What is the rx for pyoderma gangrenosum?_____

Answer: Steroids (oral and topical)

Autoimmune Skin Diseases Flashcard 5 of 5

Question: Skin changes in lichenoid tissue reactions: No answer _____

Answer: :)