Autoimmune Skin Diseases Practice Questions

Q: These skin changes developed during treatment for end-stage renal failure. What is the diagnosis?

Nephrogenic fibrosing dermopathy. ***Nephrogenic fibrosing dermopathy*** - Occurs specifically in patients with **end-stage renal disease** following exposure to **gadolinium-based contrast agents** used in MRI. - Characterized by **woody thickening** of skin, **hyperpigmentation**, and **fibrosis** predominantly affecting the extremities and trunk. *Amyloidosis* - Presents with **waxy papules** and **periorbital purpura**, not the woody skin thickening seen in NFD. - While associated with chronic kidney disease, skin changes are typically **translucent plaques** around eyes and flexural areas. *Syphilis* - Secondary syphilis causes a **copper-colored rash** on palms and soles with **condyloma lata**. - No association with **renal failure** or **gadolinium exposure**, and would be accompanied by systemic symptoms. *Scleroderma* - Features **Raynaud's phenomenon**, **sclerodactyly**, and **telangiectasias** starting distally on fingers. - Skin changes begin with **puffy fingers** progressing to **tight, shiny skin**, unlike the woody texture of NFD.

Q: Positive Nikolsky's sign is a feature of?

Pemphigus. **Explanation:** **Nikolsky’s Sign** is a clinical dermatological sign where the top layer of the skin (epidermis) slips away from the lower layers when slight tangential pressure is applied. **1. Why Pemphigus is Correct:** Pemphigus (specifically Pemphigus Vulgaris) is characterized by **acantholysis**—the loss of intercellular connections (desmosomes) between keratinocytes due to IgG autoantibodies against Desmoglein 1 and 3. Because the adhesion within the epidermis is compromised, the cells easily separate, leading to a **positive Nikolsky sign** and the formation of thin-walled, flaccid bullae. **2. Why Other Options are Incorrect:** * **Pemphigoid (Bullous Pemphigoid):** This is a **subepidermal** blistering disease where the split occurs at the dermo-epidermal junction (due to antibodies against BP180/230). The roof of the blister is the entire epidermis, making it thick and tense; thus, Nikolsky’s sign is **negative**. * **Dermatitis Herpetiformis:** This is an intensely pruritic autoimmune disease associated with Celiac disease. It involves IgA deposits at the dermal papillary tips, resulting in subepidermal vesicles. Nikolsky’s sign is **negative**. * **Rubella:** This is a viral exanthematous fever characterized by a maculopapular rash, not blistering. It does not involve loss of epidermal adhesion. **High-Yield Clinical Pearls for NEET-PG:** * **Asboe-Hansen Sign (Indirect Nikolsky):** Extension of a blister into adjacent unaffected skin when pressure is applied to the top of the bulla. Also positive in Pemphigus. * **Other Nikolsky Positive Conditions:** Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), and Staphylococcal Scalded Skin Syndrome (SSSS). * **Tzanck Smear in Pemphigus:** Shows "Acantholytic cells" (Tzanck cells)—large, round keratinocytes with hyperchromatic nuclei.

Q: Which of the following is NOT an SLE-associated rash?

Lichen planus pigmentosus. **Explanation:** **Systemic Lupus Erythematosus (SLE)** is a multisystem autoimmune disease with diverse cutaneous manifestations. The correct answer is **Lichen planus pigmentosus (LPP)** because it is a primary pigmentary disorder (a variant of Lichen Planus) characterized by grey-brown macules in sun-exposed or intertriginous areas. It is **not** etiologically or clinically associated with SLE. **Analysis of Options:** * **Lichen planus-like dermatitis (Option B):** Also known as "Lupus Erythematosus-Lichen Planus Overlap Syndrome," this is a recognized subtype where patients exhibit clinical and histological features of both diseases. * **Lupus profundus (Option C):** Also called Lupus Panniculitis, this is a chronic cutaneous LE variant involving the deep dermis and subcutaneous fat, leading to painful nodules and subsequent lipoatrophy (depressions in the skin). * **Recurrent urticaria (Option A):** Chronic urticaria or urticarial vasculitis is a well-documented "non-specific" cutaneous manifestation of SLE, often correlating with systemic activity and hypocomplementemia. **High-Yield Clinical Pearls for NEET-PG:** * **Specific LE lesions:** Malar rash (ACLE), Discoid rash (CCLE), and Psoriasiform/Annular lesions (SCLE). * **Non-specific LE lesions:** Photosensitivity, Non-scarring alopecia, Raynaud’s phenomenon, and Periungual telangiectasia. * **LPP vs. SLE:** While LPP occurs in sun-exposed areas (like SLE), it lacks the interface dermatitis and systemic autoantibodies (ANA/Anti-dsDNA) characteristic of Lupus. * **Lupus Profundus** most commonly affects the proximal extremities, buttocks, and face.

Q: Which degeneration disorder is characterized by atrophic changes of the deeper structures (e.g., fat, muscle, cartilage, and bone) involving one side of the face?

Parry Romberg syndrome. ### Explanation **Correct Answer: B. Parry Romberg Syndrome** **Parry Romberg Syndrome** (also known as Progressive Facial Hemiatrophy) is a rare neurocutaneous disorder characterized by the slow, progressive atrophy of the skin and soft tissues (fat, muscle) and, in severe cases, the underlying cartilage and bone of **one side of the face**. * **Pathogenesis:** While the exact cause is unknown, it is often considered a localized form of scleroderma (morphea en coup de sabre). * **Clinical Presentation:** It typically begins in the first or second decade of life. The atrophy usually follows a dermatomal distribution (often the trigeminal nerve) and can lead to a "sunken" facial appearance. **Why Incorrect Options are Wrong:** * **A. Scleroderma:** While Parry Romberg is related to localized scleroderma, systemic scleroderma primarily involves skin thickening (fibrosis) and internal organ involvement rather than the primary, deep-seated hemi-atrophy of bone and muscle seen in this syndrome. * **C. Miescher's Syndrome:** This refers to Granulomatous Cheilitis (recurrent swelling of the lips), which is a component of Melkersson-Rosenthal syndrome. It does not involve hemi-facial atrophy. * **D. Peutz-Jeghers Syndrome:** This is an autosomal dominant disorder characterized by hamartomatous gastrointestinal polyps and mucocutaneous hyperpigmentation (lentigines), typically on the lips and buccal mucosa. **NEET-PG High-Yield Pearls:** * **"En Coup de Sabre":** A linear form of scleroderma on the forehead/scalp that often co-exists with Parry Romberg Syndrome. * **Neurological Associations:** Patients may present with ipsilateral trigeminal neuralgia, migraine, or focal epilepsy. * **Ocular Involvement:** Enophthalmos (due to loss of periorbital fat) is a common finding.

Q: All of the following are associated with pemphigus except:

Atrophic gastritis. **Explanation:** Pemphigus is a group of autoimmune blistering diseases characterized by acantholysis (loss of intercellular connections) due to autoantibodies against desmogleins. The question focuses on the clinical associations of **Pemphigus Vulgaris (PV)** and **Paraneoplastic Pemphigus (PNP)**. **Why Atrophic Gastritis is the correct answer:** Atrophic gastritis is an autoimmune condition associated with **Pernicious Anemia** and **Vitiligo**, but it has no established pathophysiological link with Pemphigus. While both are autoimmune, they do not share the same HLA associations or syndromic clusters. **Analysis of Incorrect Options:** * **Thymoma & Myasthenia Gravis (MG):** There is a well-documented "immunological triad" between Thymoma, MG, and Pemphigus Vulgaris. The thymus is responsible for T-cell education; a thymoma can lead to a breakdown in self-tolerance, resulting in the production of autoantibodies against both acetylcholine receptors (MG) and desmogleins (Pemphigus). * **CLL (Chronic Lymphocytic Leukemia):** This is the most common malignancy associated with **Paraneoplastic Pemphigus (PNP)**. PNP is frequently triggered by B-cell lymphoproliferative disorders, including CLL, Non-Hodgkin Lymphoma, and Castleman’s disease. **NEET-PG High-Yield Pearls:** 1. **Most common association of PNP:** Non-Hodgkin Lymphoma (Adults) and Castleman’s Disease (Children). 2. **Drug-induced Pemphigus:** Most commonly caused by **Penicillamine** (thiol group drugs). 3. **HLA Association:** Pemphigus is strongly linked with **HLA-DR4** and **DRw6**. 4. **Clinical Sign:** **Nikolsky sign** is positive in Pemphigus but negative in Bullous Pemphigoid.

Q: Bullous pemphigoid is characterized by:

Blisters occurring on urticarial skin. **Explanation:** **Bullous Pemphigoid (BP)** is an autoimmune subepidermal blistering disease caused by IgG autoantibodies against **BP180 (Type XVII collagen)** and **BP230** in the hemidesmosomes of the dermo-epidermal junction. 1. **Why Option A is correct:** BP typically presents in elderly patients, often beginning with a **prodromal phase** of intense pruritus and **urticarial (hive-like) plaques**. Tense, large blisters eventually develop on these erythematous, urticarial bases or on normal-appearing skin. Because the split is subepidermal, the "roof" of the blister is the entire epidermis, making it thick and resistant to rupture. 2. **Why other options are incorrect:** * **Option B (Positive Nikolsky sign):** This is characteristic of **Pemphigus Vulgaris** (intraepidermal split). In BP, the Nikolsky sign is **negative** because the adhesion between keratinocytes is intact. * **Option C (Easily rupturing blisters):** This describes **flaccid bullae**, seen in Pemphigus. BP is characterized by **tense bullae** that do not rupture easily. * **Option D (Acantholysis):** This refers to the loss of intercellular connections (desmosomes) between keratinocytes. It is the hallmark of Pemphigus, not BP. **High-Yield Clinical Pearls for NEET-PG:** * **Direct Immunofluorescence (DIF):** Shows **linear** IgG and C3 deposits along the basement membrane zone (BMZ). * **Salt-split skin study:** Fluorescence is seen on the **roof** (epidermal side) of the split. * **Mucosal involvement:** Rare in BP (unlike Pemphigus Vulgaris). * **Treatment:** Potent topical corticosteroids (e.g., Clobetasol) or systemic steroids.

Q: A 60-year-old male presented with large tense bullae on large urticarial plaques, some of which were hemorrhagic. On examination, the bullae did not rupture easily, with the absence of Nikolsky's and bulla spread signs. Some lesions healed with milia formation. A direct immunofluorescence test of a skin biopsy was performed. Which of the following structures is most likely to be involved?

Pemphigus vulgaris. **Explanation:** The clinical presentation described—**large tense bullae** on **urticarial plaques**, absence of **Nikolsky’s sign**, and the presence of **milia**—is characteristic of subepidermal blistering diseases. **Note on the Correct Answer:** While the provided key indicates **Pemphigus Vulgaris (A)**, there appears to be a clinical mismatch. Pemphigus vulgaris typically presents with *flaccid* bullae, positive Nikolsky’s sign, and oral involvement. The description of **tense bullae** and **milia** formation strongly points towards **Epidermolysis Bullosa Acquisita (EBA)** or Bullous Pemphigoid. However, adhering to the provided key: 1. **Pemphigus Vulgaris (A):** Classically involves IgG antibodies against **Desmoglein 3 and 1**. It results in intraepidermal acantholytic blisters. (Note: Clinically, this patient's "tense" bullae and "milia" are atypical for PV). 2. **Bullous Pemphigoid (B):** Features tense bullae on urticarial bases in the elderly. It involves antibodies against **BP180/BP230** at the hemidesmosomes. While it fits the "tense bullae" description, milia are rare. 3. **Epidermolysis Bullosa Acquisita (C):** This is the most likely clinical diagnosis for the description provided. It involves antibodies against **Type VII Collagen**. It is characterized by mechanobullous lesions that heal with **milia** and scarring. 4. **Dermatitis Herpetiformis (D):** Presents as intensely pruritic, grouped vesicles on an erythematous base (extensor surfaces), associated with Celiac disease. **NEET-PG High-Yield Pearls:** * **Tense Bullae:** Subepidermal (BP, EBA, Cicatricial Pemphigoid). * **Flaccid Bullae:** Intraepidermal (Pemphigus group). * **Milia Formation:** Suggests a deep (subepidermal) blister with scarring, most commonly seen in **EBA** and Porphyria Cutanea Tarda. * **Nikolsky Sign:** Positive in Pemphigus; Negative in Bullous Pemphigoid.

Q: Desmoglein is an autoantigen in which of the following conditions?

Pemphigus. **Explanation:** The correct answer is **Pemphigus**. This group of autoimmune blistering diseases is characterized by the production of IgG autoantibodies against **Desmogleins (Dsg)**, which are calcium-dependent cell adhesion molecules (cadherins) found in **desmosomes**. Desmosomes are responsible for holding adjacent keratinocytes together. When these are targeted, it leads to **acantholysis** (loss of cell-to-cell adhesion), resulting in the formation of intraepidermal blisters. * **Pemphigus Vulgaris:** Autoantibodies against **Dsg3** (mucosal-dominant) or **Dsg1 and Dsg3** (mucocutaneous). * **Pemphigus Foliaceus:** Autoantibodies against **Dsg1** only (superficial blisters). **Why other options are incorrect:** * **Eczema (Dermatitis):** This is an inflammatory response characterized by spongiosis (intercellular edema) in the epidermis, not an autoimmune attack on desmogleins. * **Sarcoidosis:** A multisystem granulomatous disease characterized by non-caseating epithelioid granulomas. * **Vitiligo:** An autoimmune destruction of **melanocytes**, leading to depigmented patches, unrelated to desmosomal proteins. **High-Yield Clinical Pearls for NEET-PG:** * **Nikolsky Sign:** Positive in Pemphigus (denotes active acantholysis). * **Tzanck Smear:** Shows **Acantholytic cells** (Tzanck cells)—large, round keratinocytes with hyperchromatic nuclei. * **Direct Immunofluorescence (DIF):** Shows a characteristic **"Fishnet" or "Lace-like" pattern** of IgG and C3 deposits in the intercellular spaces. * **Bullous Pemphigoid (Differential):** Targets **BP180 and BP230** (Hemidesmosomes), leading to subepidermal blisters and a negative Nikolsky sign.

Q: Carpet tacking is characteristically seen in which condition?

Discoid Lupus Erythematosus (DLE). **Explanation:** **Carpet tacking sign** (also known as the **Besnier’s sign** or **Tinel’s sign**) is a pathognomonic clinical feature of **Discoid Lupus Erythematosus (DLE)**. In DLE, chronic inflammation leads to **follicular plugging**, where keratinous plugs accumulate within the dilated openings of hair follicles. When an adherent scale is forcibly removed from a long-standing DLE plaque, these keratinous plugs are pulled out along with the scale. The underside of the scale then shows small, spike-like projections resembling carpet tacks or upholstery tacks. **Analysis of Incorrect Options:** * **Systemic Lupus Erythematosus (SLE):** While DLE can occur in SLE patients, the classic "carpet tacking" is a feature of the localized, chronic discoid lesions rather than the acute malar rash of SLE, which typically does not show significant follicular plugging. * **Lichen Planus:** Characterized by **Wickham’s striae** (whitish reticular lines) and the Koebner phenomenon, but it lacks the follicular plugging seen in DLE. * **Dermatitis Herpetiformis:** A bullous disorder associated with celiac disease, characterized by intensely pruritic vesicles on extensor surfaces and **subepidermal neutrophils** on histology, not scaling or plugging. **High-Yield Clinical Pearls for NEET-PG:** * **Triad of DLE:** Erythema, Adherent Scaling, and Follicular Plugging (leading to Atrophy/Scarring). * **Histology:** DLE shows vacuolar degeneration of the basal layer and "periadnexal" lymphocytic infiltrate. * **Wolf’s Isotopic Response:** DLE lesions frequently occur at the site of healed Herpes Zoster. * **Scalp Involvement:** DLE is a common cause of **cicatricial (scarring) alopecia**.

Question 1

These skin changes developed during treatment for end-stage renal failure. What is the diagnosis?

Accepted Answer

Nephrogenic fibrosing dermopathy

Answer

Amyloidosis

Answer

Syphilis

Answer

Scleroderma

Question 2

Positive Nikolsky's sign is a feature of?

Accepted Answer

Pemphigus

Answer

Pemphigoid

Answer

Dermatitis herpetiformis

Answer

Rubella

Question 3

Which of the following is NOT an SLE-associated rash?

Accepted Answer

Lichen planus pigmentosus

Answer

Recurrent urticaria

Answer

Lichen planus-like dermatitis

Answer

Lupus profundus

Question 4

Which degeneration disorder is characterized by atrophic changes of the deeper structures (e.g., fat, muscle, cartilage, and bone) involving one side of the face?

Accepted Answer

Parry Romberg syndrome

Answer

Scleroderma

Answer

Miescher's syndrome

Answer

Peutz-Jeghers syndrome

Question 5

A female presented with skin lesions all over the body which shows a positive 'bulla spread sign'. What is this characteristic of?

Accepted Answer

Pemphigus vulgaris

Answer

Herpes gestationis

Answer

Bullous pemphigoid

Answer

Herpes simplex

Question 6

All of the following are associated with pemphigus except:

Accepted Answer

Atrophic gastritis

Answer

Thymoma

Answer

CLL (Chronic Lymphocytic Leukemia)

Answer

Myasthenia gravis

Question 7

Bullous pemphigoid is characterized by:

Accepted Answer

Blisters occurring on urticarial skin

Answer

A positive Nikolsky sign

Answer

Easily rupturing blisters

Answer

Acantholysis

Question 8

A 60-year-old male presented with large tense bullae on large urticarial plaques, some of which were hemorrhagic. On examination, the bullae did not rupture easily, with the absence of Nikolsky's and bulla spread signs. Some lesions healed with milia formation. A direct immunofluorescence test of a skin biopsy was performed. Which of the following structures is most likely to be involved?

Accepted Answer

Pemphigus vulgaris

Answer

Bullous pemphigoid

Answer

Epidermolysis bullosa acquisita

Answer

Dermatitis herpetiformis

Question 9

Desmoglein is an autoantigen in which of the following conditions?

Accepted Answer

Pemphigus

Answer

Eczema

Answer

Sarcoidosis

Answer

Vitiligo

Question 10

Carpet tacking is characteristically seen in which condition?

Accepted Answer

Discoid Lupus Erythematosus (DLE)

Answer

Systemic Lupus Erythematosus (SLE)

Answer

Lichen planus

Answer

Dermatitis herpetiformis

Autoimmune Skin Diseases — MCQs

Autoimmune Skin Diseases — MCQs

On this page

Practice by Chapter

Want unlimited practice?