Autoimmune Skin Diseases Practice Questions

Q: Flaccid bullae with mucosal involvement and intraepidermal acantholysis are characteristic of which condition?

Pemphigus vulgaris. ***Pemphigus vulgaris*** - This autoimmune blistering disease is characterized by **flaccid bullae**, **mucosal involvement**, and **intraepidermal acantholysis**, specifically targeting **desmoglein 3** and often desmoglein 1. - The blistering occurs within the epidermis due to loss of cell-to-cell adhesion, leading to a positive **Nikolsky's sign**. *Pemphigus foliaceus* - This condition involves **superficial blistering** (subcorneal acantholysis) and typically presents with **crusted erosions** rather than intact flaccid bullae, often without mucosal involvement. - It primarily targets **desmoglein 1**, leading to blistering in the more superficial layers of the epidermis. *Psoriasis* - This is a chronic inflammatory skin condition characterized by **erythematous plaques** with silvery scales, often on extensor surfaces. - It involves **epidermal hyperplasia** and inflammation, not blistering due to acantholysis. *Vitiligo* - Vitiligo is a **pigmentary disorder** characterized by **depigmented patches** of skin caused by the destruction of melanocytes. - It does not involve bullae, acantholysis, or any form of blistering.

Q: Pruritus is a feature of which of the following conditions?

Bullous pemphigoid. ***Bullous pemphigoid*** - **Pruritus**, often severe, is a common and early symptom of bullous pemphigoid, often preceding the appearance of skin lesions. - The disease involves autoantibodies against **hemidesmosomal proteins** (BPAG1, BPAG2), leading to subepidermal blister formation. *Pemphigus foliaceous* - This condition is characterized by **superficial blistering** and erosions, but **pruritus is typically mild or absent**. - Blisters form in the **granular layer of the epidermis** due to autoantibodies against desmoglein 1. *Pemphigus vulgaris* - Patients with pemphigus vulgaris present with **flaccid blisters and erosions**, mainly affecting the skin and mucous membranes, but **pruritus is not a prominent feature**. - The disease involves intraepidermal blistering caused by autoantibodies targeting **desmoglein 3 (and sometimes desmoglein 1)**. *None of the options* - This option is incorrect, as **pruritus is a characteristic symptom of bullous pemphigoid**.

Q: Which of the following statements is true regarding pemphigus vulgaris?

It is an intraepidermal blistering disease.. ***It is an intraepidermal blistering disease.*** - **Pemphigus vulgaris** is characterized by the formation of blisters *within the epidermis* due to the loss of cell-to-cell adhesion between **keratinocytes**. - This **acantholysis** results from autoantibodies targeting **desmosomes**, specifically **desmoglein 1 and 3**. *It is a subepidermal blistering disease.* - This statement is incorrect as it describes conditions like **bullous pemphigoid** or **dermatitis herpetiformis**, where blisters form *below* the epidermis. - In pemphigus vulgaris, the separation occurs *above* the basement membrane within the epidermal layer. *It primarily affects the dermal-epidermal junction.* - This is characteristic of **bullous pemphigoid** or **epidermolysis bullosa acquisita**, where the primary pathology involves the separation at the interface between the dermis and epidermis. - Pemphigus vulgaris directly affects the adhesion *within* the epidermis itself. *Antibodies are formed against basement membrane proteins.* - This is characteristic of **bullous pemphigoid**, where autoantibodies target components of the **basement membrane zone**, such as **BP180** and **BP230**. - In pemphigus vulgaris, the autoantibodies target **desmogleins** on the surface of keratinocytes, not basement membrane proteins.

Q: Which of the following statements about actinic lichen planus is false?

Associated with severe pruritus. ***Associated with severe pruritus*** - While other forms of lichen planus, especially the typical cutaneous type, are often associated with **severe pruritus**, actinic lichen planus is typically characterized by **mild or absent pruritus**. - Its presentation is often more focused on pigmentary changes and papules in sun-exposed areas rather than intense itching. *Autoimmune etiology* - **Lichen planus**, including its actinic variant, is recognized as an **autoimmune disease**. - It involves a **T-cell-mediated immune response** against basal keratinocytes. *Violaceous brown papules* - Actinic lichen planus commonly presents with **violaceous, brown, or hyperpigmented papules and plaques**. - These lesions often exhibit a subtle **annular or reticulated pattern**. *Usually affects exposed areas of body* - As its name suggests ("actinic" referring to light), this variant of lichen planus preferentially affects **sun-exposed areas** such as the face, neck, and dorsal hands. - This distribution distinguishes it from classic lichen planus, which can occur anywhere but often affects the flexor surfaces of the wrists, ankles, and oral mucosa.

Q: Nikolsky's sign is associated with which of the following conditions?

Pemphigus. ***Pemphigus*** - **Nikolsky's sign** is the **most characteristic and consistent** clinical finding in pemphigus, where slight lateral pressure on seemingly normal skin near a blister or erosion causes the epidermis to shear off, forming a new blister or denudation. - This sign indicates **intraepidermal blistering** due to the loss of cell adhesion (acantholysis) caused by autoantibodies against desmoglein proteins. - **Pemphigus is the classic condition** associated with a positive Nikolsky's sign in medical literature and examinations. *Herpes zoster* - **Herpes zoster** (shingles) is characterized by painful, vesicular eruptions in a **dermatomal distribution**, which do **not exhibit Nikolsky's sign**. - The vesicles in herpes zoster are **intraepidermal** but result from viral cytopathic effect, not acantholysis, and the roof of the vesicle remains intact with lateral pressure. *Bullous impetigo* - Bullous impetigo is a superficial skin infection caused by *Staphylococcus aureus* that produces **large, flaccid blisters**. - While **Nikolsky's sign can occasionally be positive** in bullous impetigo (particularly in staphylococcal scalded skin syndrome), it is **much less consistent and prominent** compared to pemphigus. - The key distinction is that pemphigus remains the **most characteristic association** with Nikolsky's sign in clinical practice and examinations. *All of the options* - This option is incorrect because Nikolsky's sign is **most specifically and consistently associated with pemphigus**. - While bullous impetigo may occasionally show Nikolsky's sign, **pemphigus is the classic answer** for this clinical finding in medical examinations.

Q: A 40 year old male reported with recurrent episodes of oral ulcers, large areas of denuded skin and flaccid vesiculo-bullous eruptions. Which is the most important bedside investigation helpful in establishing the diagnosis -

Tzanck smear from the floor of bulla. ***Tzanck smear from the floor of bulla*** - A Tzanck smear from the floor of a bulla will reveal **acantholytic cells** (rounded keratinocytes that have lost their intercellular connections), which are characteristic of pemphigus, consistent with recurrent oral ulcers, denuded skin, and flaccid vesiculobullous eruptions. - This **bedside test** provides a rapid diagnosis by demonstrating the cytological features of acantholysis, differentiating it from other blistering disorders. *Gram staining of blister fluid* - This test is primarily used to identify **bacterial infections** and would show the morphology and Gram-staining characteristics of any bacteria present. - It would not provide information about the **acantholysis** or autoimmune nature of the blistering condition described. *Culture and sensitivity of blister fluid* - This investigation identifies **specific bacterial pathogens** and their antibiotic susceptibilities, which is useful for treating bacterial infections. - It would not help in diagnosing **autoimmune blistering diseases** like pemphigus, where bacteria are not the primary cause of the lesions. *Skin biopsy with immunofluorescence* - While a **skin biopsy with direct immunofluorescence** is the gold standard for confirming pemphigus by detecting autoantibodies, it is an **invasive procedure** requiring laboratory processing and is not considered a rapid bedside investigation. - The question specifically asks for the "most important **bed-side investigation**" helpful in establishing the diagnosis rapidly.

Q: What is the treatment of choice for lichen planus?

Topical corticosteroids. ***Topical corticosteroids*** - **Topical corticosteroids** are the first-line treatment for localized lichen planus due to their potent **anti-inflammatory** and **immunosuppressive** effects. - They effectively reduce **itching**, **inflammation**, and the characteristic **violaceous papules** of lichen planus. *Systemic corticosteroids* - **Systemic corticosteroids** are typically reserved for widespread, severe, or refractory cases of lichen planus, not as initial treatment. - Their use is limited by potential **systemic side effects**, such as **osteoporosis**, **hypertension**, and **diabetes**. *Antihistamines* - **Antihistamines** primarily target **itching** (pruritus) associated with lichen planus but do not address the underlying **inflammatory process** or resolve the skin lesions themselves. - They may be used as an adjunct for symptomatic relief, especially for nocturnal pruritus. *Acitretin* - **Acitretin** is a **retinoid** used for severe or refractory cases of lichen planus (including erosive, oral, and hypertrophic variants), but not as first-line treatment for localized cutaneous disease. - It carries significant **teratogenic risks** and other side effects, making it unsuitable as initial therapy when topical corticosteroids are effective.

Q: Pathergy test is used for which condition?

Behçet's syndrome. ***Behçet's syndrome*** - The **pathergy test** is a diagnostic test where a sterile needle is used to prick the skin, and a positive result (erythematous papule or pustule) indicates a hyperreactivity of the skin, common in **Behçet's syndrome**. - This syndrome is a **vasculitis** characterized by recurrent oral and genital ulcers, ocular inflammation, and skin lesions, where pathergy is a characteristic feature. *Lichen planus* - This is an **inflammatory dermatosis** affecting the skin, hair, nails, and mucous membranes, characterized by "6 P's": **Pruritic, Purple, Polygonal, Planar, Papules, and Plaques**. - The pathergy test is **not used** in the diagnosis of lichen planus. *Atopic dermatitis* - Also known as **eczema**, it is a chronic, relapsing inflammatory skin condition characterized by dry, itchy skin and often associated with a personal or family history of allergies, asthma, or allergic rhinitis. - Diagnosis is primarily clinical, focusing on characteristic skin lesions and symptoms, and the **pathergy test is not applicable**. *Reiter's syndrome* - Now known as **reactive arthritis**, this condition is an autoimmune disorder that develops in response to an infection elsewhere in the body, typically genitourinary or gastrointestinal. - It classically presents with **arthritis, urethritis, and conjunctivitis** (Can't see, can't pee, can't climb a tree), and the **pathergy test is not used** for its diagnosis.

Q: Treatment of dermatitis herpetiformis:

All of the options. ***All of the options*** - **Dermatitis herpetiformis (DH)** is a chronic, intensely itchy blistering skin condition associated with **celiac disease**. - Effective management involves both a **gluten-free diet** to address the underlying autoimmune process and medications like **dapsone** or **sulfonamides** for symptomatic relief. *Gluten-free diet* - A strict **gluten-free diet** is crucial for long-term management as it addresses the underlying small intestinal enteropathy associated with **celiac disease** and **dermatitis herpetiformis**. - While it may take several months to see full skin improvement, it can eventually lead to resolution of skin lesions and reduced or eliminated need for medication. *Dapsone* - **Dapsone** is a rapidly effective medication for alleviating the intense itching and rash of **dermatitis herpetiformis**, often providing relief within 24-48 hours. - It works by inhibiting neutrophil migration and inflammation, but does not treat the underlying gluten-sensitive enteropathy. *Sulfonamide* - **Sulfonamides**, such as sulfapyridine or sulfamethoxypyridazine, can be used as an alternative for patients who cannot tolerate **dapsone** or who respond inadequately to it. - Like dapsone, these medications provide symptomatic relief by reducing inflammation and neutrophil activity in the skin, but do not address the gluten-induced intestinal damage.

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.

Question 1

Flaccid bullae with mucosal involvement and intraepidermal acantholysis are characteristic of which condition?

Accepted Answer

Pemphigus vulgaris

Answer

Pemphigus foliaceus

Answer

Psoriasis

Answer

Vitiligo

Question 2

Pruritus is a feature of which of the following conditions?

Accepted Answer

Bullous pemphigoid

Answer

Pemphigus foliaceous

Answer

Pemphigus vulgaris

Answer

None of the options

Question 3

Which of the following statements is true regarding pemphigus vulgaris?

Accepted Answer

It is an intraepidermal blistering disease.

Answer

It primarily affects the dermal-epidermal junction.

Answer

It is a subepidermal blistering disease.

Answer

Antibodies are formed against basement membrane proteins.

Question 4

Which of the following statements about actinic lichen planus is false?

Accepted Answer

Associated with severe pruritus

Answer

Violaceous brown papules

Answer

Usually affects exposed areas of body

Answer

Autoimmune etiology

Question 5

Nikolsky's sign is associated with which of the following conditions?

Accepted Answer

Pemphigus

Answer

Herpes zoster

Answer

Bullous impetigo

Answer

All of the options

Question 6

A 40 year old male reported with recurrent episodes of oral ulcers, large areas of denuded skin and flaccid vesiculo-bullous eruptions. Which is the most important bedside investigation helpful in establishing the diagnosis -

Accepted Answer

Tzanck smear from the floor of bulla

Answer

Gram staining of blister fluid

Answer

Culture and sensitivity of blister fluid

Answer

Skin biopsy with immunofluorescence

Question 7

What is the treatment of choice for lichen planus?

Accepted Answer

Topical corticosteroids

Answer

Systemic corticosteroids

Answer

Antihistamines

Answer

Acitretin

Question 8

Pathergy test is used for which condition?

Accepted Answer

Behçet's syndrome

Answer

Lichen planus

Answer

Atopic dermatitis

Answer

Reiter's syndrome

Question 9

Treatment of dermatitis herpetiformis:

Accepted Answer

All of the options

Answer

Dapsone

Answer

Sulfonamide

Answer

Gluten-free diet

Question 10

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

Autoimmune Skin Diseases — MCQs

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