Autoimmune Skin Diseases Practice Questions

Q: Which of the following is not a feature of dermatomyositis?

Salmon Patch. ***Salmon Patch*** - A **salmon patch** (also known as a nevus simplex or stork bite) is a common, benign vascular birthmark that presents as a flat, red or pink patch. - It is **not associated with dermatomyositis** and has no pathogenic link to the condition. *Gottron's patch* - **Gottron's patches** are a classic cutaneous manifestation of dermatomyositis, characterized by erythematous, violaceous, or dusky red papules or plaques over the **extensor surfaces of the metacarpophalangeal and interphalangeal joints**. - Their presence is highly suggestive of dermatomyositis, often preceding or co-occurring with muscle weakness. *Periungual telangiectasias* - **Periungual telangiectasias** are dilated capillaries around the nail folds and are a common skin manifestation of dermatomyositis. - They represent small vessel vasculopathy, a histological feature, and suggest microvascular damage often seen in systemic connective tissue diseases like dermatomyositis. *Mechanic's hands* - **Mechanic's hands** are a cutaneous feature seen in dermatomyositis (and other inflammatory myopathies like antisynthetase syndrome). - They are characterized by **hyperkeratosis**, fissuring, and scaling of the skin, particularly on the lateral and palmar aspects of the fingers, resembling the hands of a manual laborer.

Q: A child with fever presents with multiple tender erythematous skin lesions, and on microscopic examination, the skin lesions are found to have neutrophilic infiltration in the dermis. What is the diagnosis?

Sweet syndrome. ***Sweet syndrome*** - **Sweet syndrome**, also known as acute febrile neutrophilic dermatosis, presents with **fever**, **tender erythematous plaques**, and a characteristic histology of **dense neutrophilic infiltrate in the dermis** without vasculitis. - It is often triggered by **infection**, malignancy, or drugs and is more common in women, though it can occur in children. *Behçet's syndrome* - **Behçet's syndrome** is a multisystem vasculitis characterized by **recurrent oral and genital ulcers**, uveitis, and skin lesions such as erythema nodosum or papulopustular lesions, but not typically the specific neutrophilic dermatosis seen here. - The hallmark is **recurrent aphthous ulceration**, which is not mentioned in the patient's presentation. *Pyoderma gangrenosum* - **Pyoderma gangrenosum** presents as rapidly enlarging, **painful necrotic ulcers** with undermined purplish borders, often associated with inflammatory bowel disease or hematological disorders. - While it also involves neutrophilic infiltration, the clinical presentation of **tender erythematous plaques without ulceration** is not typical. *Leukemia cutis* - **Leukemia cutis** refers to infiltration of the skin by leukemic cells, which can present as papules, nodules, or plaques with **neutrophilic (myeloid) infiltration** on histology. - However, it typically occurs in patients with **known or occult hematologic malignancy**, and the lesions are usually **non-tender** and may have a violaceous hue, unlike the tender erythematous plaques of Sweet syndrome. - Sweet syndrome itself can be **paraneoplastic** and associated with myeloid malignancies, making the distinction important.

Q: Which of the following is the most characteristic feature of erythema marginatum?

Lesions are serpiginous and non-itchy.. ***Lesions are serpiginous and non-itchy.*** - **Erythema marginatum** is best characterized by its distinctive **serpiginous (snake-like)** morphology with **pink or red macules** that have pale centers. - The **non-pruritic (non-itchy)** nature is a key diagnostic feature that distinguishes it from other cutaneous manifestations in **rheumatic fever**. *Rash is transient and may appear and disappear.* - While this statement is factually correct, as erythema marginatum lesions do **migrate rapidly** and can **appear and disappear**, it is less diagnostically specific. - The **morphological features** (serpiginous pattern) and **symptomatic characteristics** (non-itchy) are more clinically useful for diagnosis than behavioral patterns. *Rash is itchy.* - This is incorrect; **erythema marginatum** is characteristically **non-pruritic**. - The presence of itching would suggest alternative dermatological conditions such as **urticaria** or **allergic dermatitis**. *Rash does not improve with cold application.* - This statement lacks clinical relevance as **cold application** is not a standard diagnostic test for erythema marginatum. - The diagnosis relies on **morphological appearance** and **clinical context** (association with rheumatic fever), not response to temperature changes.

Q: Exposure to sunlight can precipitate chronic disc-shaped skin lesions characteristic of which of the following conditions?

Discoid lupus erythematosus. ***Discoid lupus erythematosus*** - This condition is a **chronic cutaneous form of lupus** characterized by distinctive **disc-shaped lesions**, often on sun-exposed areas. - **Photosensitivity** is a prominent feature, meaning sunlight direct exposure often **exacerbates or triggers these lesions**. *Chloasma* - This refers to **melasma**, a common condition causing **dark, discolored patches** on the skin, often triggered by **hormonal changes** (e.g., pregnancy) and sun exposure. It does not typically form disc-shaped lesions. - While sunlight exposure influences its presentation, it lacks the characteristic **inflammatory disc-shaped lesions** of discoid lupus. *Dermatitis herpetiformis* - This is an **autoimmune blistering skin condition** strongly associated with **celiac disease**, characterized by intensely pruritic papules and vesicles, not disc-shaped lesions. - Its lesions are **itchy, erythematous papules and vesicles** that are symmetrically distributed, and it is not directly precipitated by sunlight exposure. *Lupus vulgaris* - This is a form of **cutaneous tuberculosis** presenting as slowly progressive, ulcerative, and destructive skin lesions. It is caused by **Mycobacterium tuberculosis** and is unrelated to sun exposure. - It involves direct **tuberculous infection of the skin**, and its clinical presentation differs significantly from the autoimmune, photosensitivity-driven lesions of discoid lupus erythematosus.

Q: A child with fever who has multiple erythematous skin lesions and, on microscopic examination, shows neutrophilic and histiocytic infiltration in the dermis is diagnosed with what?

Sweet syndrome. ***Sweet syndrome*** - Sweet syndrome (acute febrile neutrophilic dermatosis) is characterized by **fever** and the sudden onset of **erythematous plaques or nodules**. - **Histopathology** reveals diffuse **neutrophilic and histiocytic infiltration** in the dermis without vasculitis, which matches the description. *Behçet's syndrome* - Behçet's syndrome is characterized by recurrent **oral and genital ulcers**, **uveitis**, and skin lesions, but typically does not show widespread erythematous lesions with neutrophilic infiltration as the primary skin manifestation. - The histopathology may show leukocytoclastic vasculitis or neutrophilic infiltration in some cases, but the classic clinical triad distinguishes it from Sweet syndrome. *Pyoderma gangrenosum* - Pyoderma gangrenosum presents as rapidly enlarging, **painful necrotic ulcers** with undermined borders, which differs from the "multiple erythematous skin lesions" described. - While it involves neutrophilic infiltration, the clinical presentation of an ulcer is distinct from the more diffuse erythematous lesions of Sweet syndrome. *Kawasaki disease* - Kawasaki disease is a childhood vasculitis presenting with **fever** and **polymorphous rash**, along with conjunctivitis, oral changes, and extremity changes. - Histopathology shows **vasculitis** with perivascular infiltration, not the diffuse dermal neutrophilic infiltration without vasculitis seen in Sweet syndrome. - The clinical criteria (conjunctivitis, strawberry tongue, cervical lymphadenopathy) help distinguish it.

Q: A 85-year-old female developed multiple blisters on the trunk and thighs. Nikolsky's sign is negative. The lesions came on and off. The most probable diagnosis is

Bullous pemphigoid. ***Bullous pemphigoid*** - The presence of **multiple tense blisters** on the trunk and thighs in an 85-year-old female, coupled with a **negative Nikolsky's sign**, is highly characteristic of bullous pemphigoid. - This condition tends to wax and wane, causing the lesions to "come on and off," and is more common in the **elderly**. *Lichen planus* - This condition presents with **pruritic, polygonal, purple, planar papules and plaques**, not blisters. - It does not typically involve the formation of **blisters** as the primary lesion nor does it involve a negative Nikolsky's sign. *Pemphigus vulgaris* - Characterized by **flaccid blisters** that rupture easily, leading to erosions, and a **positive Nikolsky's sign**. - This is in contrast to the **tense blisters** and **negative Nikolsky's sign** described in the patient. *Lepra reaction* - Refers to **acute inflammatory episodes** occurring in patients with leprosy, often presenting as **erythematous nodules** or plaques. - It does not typically involve the formation of **blisters** on the trunk and thighs in an elderly patient without a prior diagnosis of leprosy.

Q: Quincke's disease is also known as:

Angioneurotic oedema. ***Angioneurotic oedema*** - **Quincke's disease** is an alternative name for **angioedema**, also known as angioneurotic edema. - It involves localized **subcutaneous or submucosal swelling**, often affecting the face, lips, and airways. *Norwegian scabies* - This is a severe form of **scabies**, characterized by crusted skin lesions and a high mite burden. - It is not related to angioedema or any form of swelling. *Seborrhoea oleosa* - This refers to severe **oily skin** and **dandruff**, particularly affecting the scalp and face, due to overactive sebaceous glands. - It is a dermatological condition unrelated to angioedema. *Piebaldism* - This is a rare, **autosomal dominant genetic disorder** characterized by patches of **white skin (leukoderma)** and hair (poliosis) due to the absence of melanocytes in affected areas. - It is a pigmentary disorder and has no association with angioedema.

Q: A 40-year-old male developed persistent oral ulcers, followed by multiple flaccid bullae on the trunk and extremities. Direct immunofluorescence examination of a skin biopsy showed intercellular IgG deposits in the epidermis. What is the most probable diagnosis?

Pemphigus vulgaris. ***Pemphigus vulgaris*** - The presence of **persistent oral ulcers** followed by **flaccid bullae** on the trunk and extremities are classic clinical features. - **Direct immunofluorescence (DIF)** showing **intercellular IgG deposits** in the epidermis confirms the diagnosis, indicating antibodies against **desmogleins** within the desmosomes. *Bullous Pemphigoid* - Characterized by **tense bullae**, unlike the flaccid bullae seen in this case, and typically affects older individuals. - DIF would show **linear IgG and C3 deposits along the dermal-epidermal junction**, not intercellular epidermal deposits. *Bullous Lupus erythematosus* - This condition is rare and presents with **tense bullae** and other systemic manifestations of lupus erythematosus. - DIF usually shows granular or linear deposits of **IgG, IgA, or C3 at the dermal-epidermal junction**, sometimes in a "lupus band" pattern, but not intercellular epidermal IgG. *Epidermolysis bullosa acquisita* - Presents with skin fragility and **blisters in response to trauma**, particularly on acral surfaces, with features resembling **dystrophic epidermolysis bullosa**. - DIF reveals **linear IgG or IgA deposits along the dermal-epidermal junction** targeting type VII collagen, distinguishing it from pemphigus vulgaris.

Q: A 50-year-old female presents with blisters and erosions on the skin and mucous membranes, most commonly inside the mouth. What is the most likely diagnosis?

Pemphigus vulgaris. ***Pemphigus vulgaris*** - This condition is characterized by **flaccid blisters** that easily rupture, leading to painful erosions, often starting in the **oral mucosa** (50-70% of cases). - It is an **autoimmune disease** with antibodies against **desmoglein 3 (mucous membranes) and desmoglein 1 (skin)**, causing **intraepidermal blistering**. - **Nikolsky sign positive** - lateral pressure causes sloughing of skin. *Dermatitis herpetiformis* - This presents with intensely **pruritic (itchy) grouped vesicles** on extensor surfaces (elbows, knees, buttocks), not flaccid blisters with oral involvement. - It is strongly associated with **celiac disease** and characterized by **IgA deposition in the dermal papillae**. *Bullous pemphigoid* - Presents with **tense blisters** on an erythematous base, typically in **elderly patients (>60 years)**. - **Oral mucosa usually spared** or involved late in the disease course. - Involves autoantibodies against **hemidesmosomal proteins (BP180 and BP230)**, leading to **subepidermal blistering**. *Erythema multiforme* - Characterized by **target lesions** and can involve mucous membranes, but typically presents acutely with symmetrical distribution. - Often triggered by **infections (HSV) or medications**, not an autoimmune blistering disease. - Lacks the chronic, progressive oral erosions typical of pemphigus vulgaris.

Q: 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?

Systemic lupus erythematosus. ***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.

Question 1

Which of the following is not a feature of dermatomyositis?

Accepted Answer

Salmon Patch

Answer

Periungual telangiectasias

Answer

Gottron's patch

Answer

Mechanic's hands

Question 2

A child with fever presents with multiple tender erythematous skin lesions, and on microscopic examination, the skin lesions are found to have neutrophilic infiltration in the dermis. What is the diagnosis?

Accepted Answer

Sweet syndrome

Answer

Behcet's syndrome

Answer

Pyoderma gangrenosum

Answer

Leukemia cutis

Question 3

Which of the following is the most characteristic feature of erythema marginatum?

Accepted Answer

Lesions are serpiginous and non-itchy.

Answer

Rash is transient and may appear and disappear.

Answer

Rash is itchy.

Answer

Rash does not improve with cold application.

Question 4

Exposure to sunlight can precipitate chronic disc-shaped skin lesions characteristic of which of the following conditions?

Accepted Answer

Discoid lupus erythematosus

Answer

Dermatitis herpetiformis

Answer

Lupus vulgaris

Answer

Chloasma

Question 5

A child with fever who has multiple erythematous skin lesions and, on microscopic examination, shows neutrophilic and histiocytic infiltration in the dermis is diagnosed with what?

Accepted Answer

Sweet syndrome

Answer

Pyoderma gangrenosum

Answer

Kawasaki disease

Answer

Behçet's syndrome

Question 6

A 85-year-old female developed multiple blisters on the trunk and thighs. Nikolsky's sign is negative. The lesions came on and off. The most probable diagnosis is

Accepted Answer

Bullous pemphigoid

Answer

Pemphigus vulgaris

Answer

Lepra reaction

Answer

Lichen planus

Question 7

Quincke's disease is also known as:

Accepted Answer

Angioneurotic oedema

Answer

Norwegian scabies

Answer

Seborrhoea oleosa

Answer

Piebaldism

Question 8

A 40-year-old male developed persistent oral ulcers, followed by multiple flaccid bullae on the trunk and extremities. Direct immunofluorescence examination of a skin biopsy showed intercellular IgG deposits in the epidermis. What is the most probable diagnosis?

Accepted Answer

Pemphigus vulgaris

Answer

Bullous Pemphigoid

Answer

Bullous Lupus erythematosus

Answer

Epidermolysis bullosa acquisita

Question 9

A 50-year-old female presents with blisters and erosions on the skin and mucous membranes, most commonly inside the mouth. What is the most likely diagnosis?

Accepted Answer

Pemphigus vulgaris

Answer

Dermatitis herpetiformis

Answer

Bullous pemphigoid

Answer

Erythema multiforme

Question 10

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?

Accepted Answer

Systemic lupus erythematosus

Answer

Dermatomyositis

Answer

Progressive systemic sclerosis

Answer

Rheumatoid arthritis

Autoimmune Skin Diseases — MCQs

Autoimmune Skin Diseases — MCQs

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