Autoimmune Skin Diseases — MCQs

Autoimmune Skin Diseases Indian Medical PG Practice Questions and MCQs

Question 31: Heliotrope rash is seen in which condition?

A. Dermatitis herpetiformis
B. Polymyositis
C. Inclusion body myositis
D. Dermatomyositis (Correct Answer)

Explanation: **Explanation:** **Dermatomyositis** is an idiopathic inflammatory myopathy characterized by symmetrical proximal muscle weakness and distinctive cutaneous findings. The **Heliotrope rash** is considered a pathognomonic sign of this condition. It presents as a violaceous (reddish-purple) eruption on the upper eyelids, often accompanied by periorbital edema. The name is derived from the *Heliotropium* flower, which shares this characteristic purple hue. **Analysis of Options:** * **Dermatomyositis (Correct):** It is the only condition among the choices that features both the Heliotrope rash and Gottron’s papules (violaceous papules over bony prominences like MCP/PIP joints). * **Polymyositis:** While it shares the same proximal muscle weakness as dermatomyositis, it is strictly a muscle disease and **lacks** the characteristic cutaneous manifestations (no rash). * **Inclusion Body Myositis:** This typically affects older individuals and involves distal muscles (like finger flexors) asymmetrically. It does not present with a Heliotrope rash. * **Dermatitis Herpetiformis:** This is an intensely pruritic, blistering skin disease associated with Celiac disease. It presents with grouped vesicles on the elbows, knees, and buttocks, not a facial violaceous rash. **High-Yield Clinical Pearls for NEET-PG:** * **Gottron’s Papules:** The most specific sign of Dermatomyositis. * **Shawl Sign/V-Sign:** Erythema over the upper back/shoulders and anterior chest. * **Holster Sign:** Erythema on the lateral thighs. * **Mechanic’s Hands:** Hyperkeratosis and fissuring of the palms and lateral fingers (associated with Anti-Jo-1 antibodies). * **Malignancy:** Dermatomyositis in adults is frequently associated with internal malignancies (paraneoplastic syndrome), necessitating age-appropriate cancer screening.

Question 32: Heliotrope rash is seen in which of the following conditions?

A. Dermatomyositis (Correct Answer)
B. Polymyositis
C. Scleroderma
D. Pityriasis rosea

Explanation: **Explanation:** **Heliotrope rash** is a pathognomonic cutaneous feature of **Dermatomyositis**. It is characterized by a symmetric, violaceous (purplish) to dusky red erythema involving the upper eyelids, often accompanied by periorbital edema. The name is derived from the *Heliotropium* flower, which shares a similar purple hue. This rash is a primary diagnostic criterion and is often one of the earliest signs of the disease. **Analysis of Options:** * **Dermatomyositis (Correct):** An idiopathic inflammatory myopathy that presents with proximal muscle weakness and characteristic skin findings like the Heliotrope rash, Gottron papules, and the Shawl sign. * **Polymyositis:** While clinically similar to dermatomyositis regarding proximal muscle weakness, it **lacks** the characteristic cutaneous manifestations (no rash). * **Scleroderma:** Characterized by skin thickening and tightening (sclerodactyly) and Raynaud’s phenomenon, but does not feature a violaceous eyelid rash. * **Pityriasis Rosea:** A self-limiting inflammatory condition presenting with a "Herald patch" followed by a "Christmas tree" distribution of scaly papules on the trunk. **High-Yield Clinical Pearls for NEET-PG:** * **Gottron Papules:** Violaceous flat-topped papules over the dorsal aspects of interphalangeal and metacarpophalangeal joints (also pathognomonic for Dermatomyositis). * **Mechanic’s Hands:** Hyperkeratosis and fissuring of the palms and lateral fingers; associated with **Anti-Jo-1 antibodies** and interstitial lung disease. * **Malignancy:** Dermatomyositis in adults is frequently associated with internal malignancies (paraneoplastic syndrome); age-appropriate cancer screening is mandatory. * **Holster Sign:** Erythema on the lateral aspect of the thighs.

Question 33: Which condition is characterized by arthritis mutilans?

A. Lichen planus
B. Psoriasis (Correct Answer)
C. Staphylococcal scalded skin syndrome
D. Eczema

Explanation: **Explanation:** **Arthritis mutilans** is a severe, destructive form of inflammatory arthritis characterized by the resorption of bones and the collapse of soft tissue. It is a classic, high-yield manifestation of **Psoriatic Arthritis (PsA)**, occurring in approximately 5% of patients with PsA. The hallmark clinical feature is the **"telescoping finger"** (main en lorgnette), where the digits can be pulled back to their original length due to extensive osteolysis. Radiologically, this presents as the **"pencil-in-cup" deformity**, where the proximal bone erodes into a point that fits into the widened base of the distal bone. **Analysis of Incorrect Options:** * **Lichen planus:** An inflammatory condition of the skin and mucous membranes characterized by the "6 Ps" (Planar, Purple, Polygonal, Pruritic, Papules, and Plaques). It does not involve the joints or cause bone destruction. * **Staphylococcal scalded skin syndrome (SSSS):** A toxin-mediated blistering disease caused by *Staphylococcus aureus*. It affects the superficial epidermis (desmoglein-1) and presents with skin peeling; it has no association with chronic arthritis. * **Eczema:** A broad term for dermatitis characterized by pruritus and inflammation. While it can be chronic, it is limited to the dermo-epidermal layers and does not cause systemic joint destruction. **NEET-PG High-Yield Pearls:** * **Moll and Mason Criteria:** Used for classifying Psoriatic Arthritis. * **HLA Association:** Psoriatic arthritis is strongly associated with **HLA-B27**. * **Nail Changes:** Pitting and onycholysis are strong predictors of joint involvement in psoriasis patients. * **Radiology:** Look for "pencil-in-cup" deformity and "Gull-wing" appearance in the distal interphalangeal (DIP) joints.

Question 34: Gottron's papules are a characteristic finding in which of the following conditions?

A. Dermatomyositis (Correct Answer)
B. Scleroderma
C. Mixed connective tissue disorder
D. Pemphigus vulgaris

Explanation: **Explanation:** **Dermatomyositis** is an idiopathic inflammatory myopathy characterized by proximal muscle weakness and distinct cutaneous manifestations. **Gottron’s papules** are considered a **pathognomonic** (highly specific) sign of this condition. They are violaceous, flat-topped, lichenoid papules typically found over the dorsal aspects of the interphalangeal and metacarpophalangeal joints. **Analysis of Options:** * **Dermatomyositis (Correct):** Along with Gottron’s papules, other classic signs include the **Heliotrope rash** (violaceous edema of the eyelids) and **Gottron’s sign** (macular erythema over joints). * **Scleroderma:** Characterized by skin tightening (sclerodactyly), Raynaud’s phenomenon, and "salt and pepper" pigmentation. It does not feature Gottron’s papules. * **Mixed Connective Tissue Disorder (MCTD):** This is an overlap syndrome (SLE, Scleroderma, and Polymyositis) characterized by high titers of **anti-U1 RNP antibodies**. While it can share features of dermatomyositis, Gottron’s papules specifically point toward a primary diagnosis of dermatomyositis. * **Pemphigus Vulgaris:** An autoimmune blistering disease caused by antibodies against **Desmoglein 3**. It presents with flaccid bullae and oral erosions, not inflammatory papules over joints. **High-Yield Clinical Pearls for NEET-PG:** * **Shawl Sign:** Erythema over the upper back and shoulders. * **V-Sign:** Erythema over the anterior neck and upper chest. * **Mechanic’s Hands:** Hyperkeratotic, fissured skin on the lateral fingers (associated with **Anti-Jo-1 antibodies** and interstitial lung disease). * **Malignancy:** Dermatomyositis in adults is associated with an increased risk of internal malignancies (e.g., ovarian, lung, breast). * **Holster Sign:** Erythema on the lateral thighs.

Question 35: HLA DR3 is associated with which of the following conditions?

A. Dermatitis herpetiformis (Correct Answer)
B. Pemphigus vulgaris
C. Behcet disease
D. Psoriasis vulgaris

Explanation: **Explanation:** The correct answer is **Dermatitis herpetiformis (DH)**. **1. Why Dermatitis herpetiformis is correct:** Dermatitis herpetiformis is a chronic, intensely pruritic autoimmune blistering disease strongly associated with **Gluten-Sensitive Enteropathy (Celiac Disease)**. The genetic predisposition is linked to the Major Histocompatibility Complex (MHC) Class II molecules, specifically **HLA-DR3** and **HLA-DQ2/DQ8**. In these patients, IgA antibodies against tissue transglutaminase (tTG) cross-react with epidermal transglutaminase, leading to subepidermal blisters. **2. Why the other options are incorrect:** * **Pemphigus vulgaris:** This is primarily associated with **HLA-DR4** and **HLA-DRw6**. It is characterized by IgG antibodies against Desmoglein 3, leading to intraepidermal acantholytic blisters. * **Behcet disease:** This multi-system inflammatory disorder is strongly linked to **HLA-B51**. It presents with the classic triad of oral ulcers, genital ulcers, and uveitis. * **Psoriasis vulgaris:** The strongest genetic association for chronic plaque psoriasis is **HLA-Cw6** (within the PSORS1 locus). **Clinical Pearls for NEET-PG:** * **DH Histopathology:** Characterized by **neutrophilic microabscesses** at the tips of dermal papillae. * **Direct Immunofluorescence (DIF):** Shows **granular IgA deposits** in the dermal papillae (Gold Standard for diagnosis). * **Treatment of Choice:** **Dapsone** (provides rapid symptomatic relief) along with a **Gluten-free diet**. * **Mnemonic for HLA-DR3:** "DR3 is for the **3** D's: **D**ermatitis herpetiformis, **D**iabetes (Type 1), and **D**LE/SLE."

Question 36: Which of the following is not seen in Dermatomyositis?

A. Gottron's papules
B. Heliotrope rash
C. Mechanic's hands
D. Salmon Rash (Correct Answer)

Explanation: **Explanation:** The correct answer is **D. Salmon Rash**. This rash is a characteristic feature of **Systemic Onset Juvenile Idiopathic Arthritis (Still’s Disease)**, not Dermatomyositis. It is typically an evanescent (transient), non-pruritic, salmon-pink maculopapular eruption that coincides with fever spikes. **Why the other options are seen in Dermatomyositis:** * **Gottron’s Papules (Option A):** These are considered **pathognomonic** for Dermatomyositis. They are violaceous, flat-topped papules found over the dorsal aspects of the interphalangeal and metacarpophalangeal joints. * **Heliotrope Rash (Option B):** A classic sign consisting of a violaceous (lilac) eruption on the upper eyelids, often associated with periorbital edema. * **Mechanic’s Hands (Option C):** Characterized by hyperkeratosis, scaling, and fissuring on the palmar and lateral aspects of the fingers. While seen in Dermatomyositis, it is strongly associated with **Anti-synthetase syndrome** (Anti-Jo-1 antibodies). **High-Yield Clinical Pearls for NEET-PG:** * **Shawl Sign:** Erythema over the upper back and shoulders. * **V-Sign:** Erythema over the anterior neck and upper chest. * **Holster Sign:** Poikiloderma on the lateral aspects of the thighs. * **Malignancy:** Dermatomyositis in adults is frequently a **paraneoplastic syndrome** (most commonly associated with ovarian, lung, and gastric cancers). * **Antibodies:** **Anti-Mi-2** is highly specific for Dermatomyositis; **Anti-Jo-1** is linked to interstitial lung disease (ILD).

Question 37: A 37-year-old female presents with multiple, linear, itchy wheals, with itching for 30 minutes at the site. What is the most probable diagnosis?

A. Dermatographic urticaria (Correct Answer)
B. Pressure urticaria
C. Acute urticaria
D. Chronic urticaria

Explanation: **Explanation:** The clinical presentation of **linear, itchy wheals** appearing shortly after scratching or firm stroking is the hallmark of **Dermatographic Urticaria** (also known as "skin writing" or urticaria factitia). **1. Why Dermatographic Urticaria is correct:** This is the most common form of physical urticaria. It is caused by the release of histamine from mast cells in response to **mechanical shear forces** (like scratching or friction). The wheals typically appear within minutes, are confined to the site of trauma, and resolve within 30–60 minutes. The "linear" pattern mentioned in the question is a classic sign of the patient scratching the skin. **2. Why other options are incorrect:** * **Pressure Urticaria:** This typically presents as deep, painful swelling (rather than itchy linear wheals) that occurs **4–8 hours after** sustained pressure (e.g., from tight waistbands or standing). * **Acute Urticaria:** Defined as hives lasting <6 weeks. While it presents with wheals, they are usually spontaneous and generalized, not specifically linear or triggered by stroking. * **Chronic Urticaria:** Defined as hives occurring most days of the week for >6 weeks. Like acute urticaria, these are typically spontaneous and not localized to lines of friction. **Clinical Pearls for NEET-PG:** * **Diagnosis:** Usually clinical; can be confirmed using a **frictest** or a **dermographometer**. * **Treatment:** First-line treatment is **H1 antihistamines** (e.g., Cetirizine, Loratadine). * **Darier’s Sign:** Do not confuse dermatographism with Darier’s sign (wheal and flare formation upon stroking a lesion of **Mastocytosis/Urticaria Pigmentosa**). * **Prevalence:** It affects approximately 2–5% of the general population.

Question 38: Which of the following statements is false regarding scleroderma?

A. Digital ulceration
B. Gastroesophageal Reflux Disease (GERD)
C. Mask-like facies
D. Female preponderance of 9:1 (Correct Answer)

Explanation: ### Explanation **1. Why Option D is the Correct Answer (The False Statement):** While Systemic Sclerosis (Scleroderma) does show a significant female predilection, the ratio is typically cited as **3:1 to 5:1**. A ratio of **9:1** is characteristic of **Systemic Lupus Erythematosus (SLE)**. In NEET-PG, distinguishing between these female-to-male ratios is a common way to differentiate between connective tissue disorders. **2. Analysis of Other Options (True Statements):** * **A. Digital Ulceration:** This is a hallmark of systemic sclerosis, resulting from severe Raynaud’s phenomenon and chronic digital ischemia. These ulcers are painful, slow to heal, and often lead to "pitting scars" on the fingertips. * **B. Gastroesophageal Reflux Disease (GERD):** The esophagus is the most common internal organ involved (up to 90% of cases). Fibrosis leads to lower esophageal sphincter (LES) incompetence and dysmotility, causing severe GERD and "watermelon stomach" (GAVE). * **C. Mask-like Facies:** Cutaneous fibrosis leads to a loss of expression, microstomia (small mouth), thinning of lips, and radial furrowing around the mouth (Mauskopf facies). **3. High-Yield Clinical Pearls for NEET-PG:** * **Classification:** Divided into **Limited** (CREST syndrome) and **Diffuse** (rapid skin thickening, early visceral involvement). * **Antibody Markers:** * **Anti-Scl-70 (Anti-topoisomerase I):** Specific for Diffuse Scleroderma (associated with Pulmonary Fibrosis). * **Anti-Centromere:** Specific for Limited Scleroderma/CREST (associated with Pulmonary Hypertension). * **Anti-RNA Polymerase III:** Associated with **Scleroderma Renal Crisis**. * **First Sign:** Raynaud’s phenomenon is usually the earliest clinical manifestation.

Question 39: A butterfly rash is typically seen in which of the following conditions?

A. Herpes simplex
B. Systemic lupus erythematosus (Correct Answer)
C. Scleroderma
D. None of the above

Explanation: **Explanation:** **Systemic Lupus Erythematosus (SLE)** is the correct answer because the **butterfly rash** (also known as a **malar rash**) is the classic cutaneous hallmark of Acute Cutaneous Lupus Erythematosus (ACLE). **Why it occurs:** The rash is a fixed, erythematous, flat or raised eruption over the malar eminences (cheeks) and the bridge of the nose. A key diagnostic feature for NEET-PG is that it **spares the nasolabial folds**, which helps differentiate it from seborrheic dermatitis. It is often triggered or exacerbated by ultraviolet (UV) light exposure (photosensitivity). **Analysis of Incorrect Options:** * **Herpes Simplex:** Typically presents as grouped vesicles on an erythematous base ("dewdrops on a rose petal"). It is localized (e.g., Herpes Labialis) and does not follow a malar distribution. * **Scleroderma:** Characterized by skin thickening and tightening (sclerosis). While it affects the face (leading to "mask-like facies" or "microstomia"), it does not present with a transient malar butterfly rash. **High-Yield Clinical Pearls for NEET-PG:** * **Differential Diagnosis:** The main differential for a butterfly rash is **Erysipelas** (which is painful, raised, and has a sharp border) and **Rosacea** (which involves the nasolabial folds and may show telangiectasia or pustules). * **Histopathology of SLE:** Shows vacuolar degeneration of the basal layer and a "Lupus Band Test" (granular IgG/C3 deposits at the dermo-epidermal junction). * **Systemic Association:** The presence of a malar rash is one of the ACR/SLICC criteria for diagnosing SLE.

Question 40: Moderate to high titres of anti-DNA and anti-Smith antibodies are almost pathognomonic of which condition?

A. Systemic Lupus Erythematosus (SLE) (Correct Answer)
B. Erythema Multiforme (EM)
C. Lichen planus
D. All of the above

Explanation: ### Explanation **Correct Answer: A. Systemic Lupus Erythematosus (SLE)** **Medical Concept:** Systemic Lupus Erythematosus (SLE) is a multisystem autoimmune disease characterized by the production of various autoantibodies. While **Anti-nuclear antibody (ANA)** is the most sensitive screening test (positive in >95% of cases), it lacks specificity. In contrast, **Anti-dsDNA** and **Anti-Smith (Anti-Sm)** antibodies are highly specific for SLE. * **Anti-dsDNA:** Its levels often correlate with disease activity, particularly lupus nephritis. * **Anti-Smith:** It is directed against small nuclear ribonucleoproteins (snRNPs). While only present in about 10–30% of patients, it is considered **pathognomonic** because it is rarely found in any other condition. **Why other options are incorrect:** * **B. Erythema Multiforme (EM):** This is a hypersensitivity reaction, most commonly triggered by infections (like Herpes Simplex Virus) or drugs. It is not characterized by specific autoantibodies like Anti-Sm. * **C. Lichen Planus:** This is a T-cell mediated chronic inflammatory condition affecting the skin and mucosa. Diagnosis is clinical and histological (Civatte bodies, Saw-tooth rete ridges), not serological. * **D. All of the above:** Incorrect, as the mentioned antibodies are specific to the pathogenesis of SLE only. **High-Yield Clinical Pearls for NEET-PG:** * **Most Sensitive Test for SLE:** ANA (Best initial screening). * **Most Specific Tests for SLE:** Anti-dsDNA and Anti-Smith. * **Drug-Induced Lupus:** Characterized by **Anti-Histone antibodies**; Anti-dsDNA is usually negative. * **Neonatal Lupus/Congenital Heart Block:** Strongly associated with **Anti-Ro (SS-A)** and **Anti-La (SS-B)** antibodies. * **Mixed Connective Tissue Disease (MCTD):** Associated with high titers of **Anti-U1 RNP**.

Practice by Chapter

Lupus Erythematosus: Cutaneous Forms

Practice Questions

Lupus Erythematosus: Systemic with Skin Manifestations

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Dermatomyositis

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Scleroderma and Morphea

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Mixed Connective Tissue Disease

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Sjögren's Syndrome: Cutaneous Manifestations

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Relapsing Polychondritis

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Autoimmune Thyroid Disease and the Skin

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Immunobullous Disorders

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Vasculitis

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Diagnostic Methods in Autoimmune Dermatoses

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Management of Autoimmune Skin Diseases

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