Autoimmune Skin Diseases Practice Questions

Q: A 32-year-old woman presents with multiple pruritic papules and vesicles on her elbows and knees. She reports a history of gluten sensitivity. Skin biopsy shows granular IgA deposits in dermal papillae. Which of the following is most likely to be elevated in this patient's serum?

Anti-tissue transglutaminase antibodies. ***Anti-tissue transglutaminase antibodies*** - The patient's presentation with **pruritic papules and vesicles on elbows and knees**, history of **gluten sensitivity**, and **IgA deposits in dermal papillae** points to **dermatitis herpetiformis**. - **Dermatitis herpetiformis** is strongly associated with **celiac disease**, which involves an immune response to **gluten**, leading to elevated **anti-tissue transglutaminase (tTG) antibodies**. *Anti-DNA antibodies* - **Anti-DNA antibodies**, particularly **anti-dsDNA**, are characteristic markers for **systemic lupus erythematosus (SLE)**, a systemic autoimmune disease not suggested by the clinical picture or biopsy findings. - SLE presents with a wide range of symptoms including joint pain, malar rash, renal involvement, and serositis, which are not described here. *Anti-type VII collagen antibodies* - **Anti-type VII collagen antibodies** are associated with **epidermolysis bullosa acquisita (EBA)**, a subepidermal blistering disease. - EBA lesions are typically more **tense bullae** and often associated with trauma, and the immunofluorescence pattern is different from the granular IgA deposits seen in dermatitis herpetiformis. *Anti-BP180 antibodies* - **Anti-BP180 antibodies** (also known as anti-BPAg2) are the primary autoantibodies found in **bullous pemphigoid**, another subepidermal blistering disease. - **Bullous pemphigoid** typically presents with large, tense blisters in elderly patients, and direct immunofluorescence shows **linear IgA/IgG deposition along the basement membrane zone**, not granular IgA in dermal papillae.

Q: A 58-year-old woman presents with tense bullae on an erythematous base, primarily affecting her trunk and extremities. The lesions developed over the past 3 weeks. Nikolsky sign is negative. Skin biopsy shows subepidermal bullae with eosinophilic infiltrate. Direct immunofluorescence shows linear deposits of IgG and C3 at the basement membrane zone. Which of the following is the target antigen in this condition?

BP180/BP230. ***BP180/BP230*** - The clinical presentation of **tense bullae**, negative **Nikolsky sign**, subepidermal bullae with **eosinophilic infiltrate**, and **linear IgG and C3 deposition at the basement membrane zone** are classic features of **bullous pemphigoid**. - **BP180** (also known as type XVII collagen) and **BP230** are hemidesmosomal proteins that serve as the primary target antigens in bullous pemphigoid. *Type IV collagen* - **Type IV collagen** is a major component of the **basement membrane**, but it is not the target antigen in bullous pemphigoid. - Antibodies against type IV collagen may be involved in **Goodpasture syndrome**, which affects the kidneys and lungs, not primarily the skin in this manner. *Type VII collagen* - **Type VII collagen** is found in the **anchoring fibrils** beneath the basement membrane. - Antibodies against **type VII collagen** are characteristic of **epidermolysis bullosa acquisita**, which typically presents with **fragile skin, trauma-induced blistering**, and scarring, differentiating it from this case. *Desmoglein-3* - **Desmoglein-3** is a **desmosomal protein** that is a primary target antigen in **pemphigus vulgaris**, especially the **mucosal dominant form**. - **Pemphigus vulgaris** is characterized by **flaccid bullae, painful erosions**, and a **positive Nikolsky sign**, which are not consistent with the patient's presentation.

Q: A skin biopsy shows acantholysis with intraepidermal blistering. Which immunofluorescence pattern would confirm pemphigus vulgaris?

Fishnet pattern of IgG. ***Fishnet pattern of IgG*** - A **fishnet or reticular pattern** of **IgG deposition** on direct immunofluorescence (DIF) is characteristic of **pemphigus vulgaris**, indicating antibodies targeting **desmoglein 1 and 3** in the intracellular spaces of the epidermis. - This pattern corresponds to the **acantholysis** observed on biopsy, where loss of cell adhesion leads to intraepidermal blistering. *Linear IgA deposits* - **Linear IgA deposits** at the **dermal-epidermal junction** are characteristic of **linear IgA bullous dermatosis**, a blistering disorder distinct from pemphigus. - This pattern signifies **antibodies targeting components of the basement membrane zone**, not intraepidermal desmogleins. *Granular IgG deposits* - **Granular IgG deposits** in the skin are typically seen in conditions like **lupus erythematosus** or **dermatitis herpetiformis** when IgA is targeted, signifying immune complex deposition or specific antigen targeting. - This pattern is not associated with the pathogenesis of pemphigus vulgaris, which involves antibodies against desmosomal proteins. *Linear C3 deposits* - **Linear C3 deposits**, particularly at the **dermal-epidermal junction**, are a hallmark of **bullous pemphigoid**, often accompanied by linear IgG or IgA. - This indicates **complement activation** at the basement membrane zone, leading to subepidermal blistering, not the intraepidermal blistering seen in pemphigus vulgaris.

Q: Periungual telangiectasias are pathognomonic signs of the following except:

Polyarteritis nodosa. ***Polyarteritis nodosa*** - **Periungual telangiectasias** are generally *not* a characteristic or pathognomonic finding in Polyarteritis nodosa (PAN). - PAN is a **necrotizing vasculitis** primarily affecting medium-sized arteries, often presenting with systemic symptoms, **skin nodules**, livedo reticularis, and mononeuritis multiplex, but not typical periungual changes. *Systemic sclerosis* - **Periungual telangiectasias** are a common and characteristic finding in systemic sclerosis, often seen as part of the broader microvascular damage. - They tend to be prominent and can be associated with **Raynaud's phenomenon** and digital ischemia. - Part of the CREST syndrome features. *Dermatomyositis* - **Periungual telangiectasias** are a characteristic finding in dermatomyositis, along with other nail fold changes. - They are associated with other cutaneous features like **Gottron's papules**, heliotrope rash, and shawl sign. - Nail fold capillary changes are important diagnostic clues in inflammatory myopathies. *Lupus erythematosus* - **Periungual telangiectasias** are frequently observed in patients with systemic lupus erythematosus (SLE) and are considered a clinical sign of microvascular involvement. - They can be part of the broader mucocutaneous manifestations, which also include **malar rash** and discoid lesions.

Q: Acute febrile neutrophilic dermatosis is seen in-

Sweet syndrome. ***Sweet syndrome*** - Sweet syndrome is also known as **Acute febrile neutrophilic dermatosis**. - It presents with **fever**, painful erythematous plaques, and a prominent **neutrophilic infiltrate** in the dermis. *Behcet's syndrome* - Behcet's syndrome is characterized by **recurrent oral and genital ulcers**, uveitis, and skin lesions like **erythema nodosum** or **pathergy**. - It is a systemic vasculitis, not typically presenting as acute febrile neutrophilic dermatosis. *Haberman syndrome* - Haberman syndrome is better known as **Pityriasis lichenoides et varioliformis acuta (PLEVA)**. - It is a rare skin condition characterized by an acute eruption of **papules** and **erosions** that can resemble **chickenpox**. *Kasabach-Merritt syndrome* - This syndrome is a rare disorder involving **vascular tumors** (e.g., hemangiomas) that lead to profound **thrombocytopenia** and **consumptive coagulopathy**. - It does not present with acute febrile neutrophilic dermatosis.

Q: A patient with typical cutaneous lesions, slightly elevated red or purple macules often covered by gray or yellow adherent scales. Forceful removal of the scale reveals numerous ‘carpet tack’ extensions. The lesion is:

DLE. ***DLE*** - **Discoid lupus erythematosus (DLE)** lesions are characterized by **erythematous-to-violaceous plaques**, often with **follicular plugging** and a **firmly adherent scale**. - The "carpet tack" sign refers to the painful, prickly projections observed on the undersurface of a removed scale, indicating keratinous plugs within hair follicles, which is highly suggestive of DLE. *Scleroderma* - **Scleroderma** involves **fibrosis** of the skin, leading to hardening and thickening, often preceded by Raynaud's phenomenon. - It does not typically present with elevated red or purple macules with adherent scales or the "carpet tack" sign. *SLE* - **Systemic lupus erythematosus (SLE)** is a multi-system autoimmune disease that can have cutaneous manifestations, but these are often more diffuse (**malar rash**, photosensitivity) or non-scarring. - While DLE can occur in SLE patients, the description specifically points to the localized, scarring nature of DLE rather than the systemic features of SLE itself. *Lichen planus* - **Lichen planus** typically presents with **pruritic, polygonal, planar, purple papules and plaques** (the "6 Ps"). - While it can have scaling, it does not exhibit the "carpet tack" sign or the distinct follicular plugging seen in DLE.

Q: A young female presented with lacy linear lesions on tongue for a month with elongation of nail fold beyond the nail bed. What is the diagnosis –

Lichen planus. ***Lichen planus*** - **Lacy linear lesions on the tongue** are characteristic of **Wickham's striae**, a hallmark feature of oral lichen planus. - **Elongation of the nail fold beyond the nail bed** (known as pterygium formation) is a specific nail finding seen in lichen planus. *Candidiasis* - Oral candidiasis typically presents as **white, creamy patches** that can be scraped off, unlike the lacy lesions described. - It does not typically cause **nail fold elongation** or similar specific nail changes. *Psoriasis* - While psoriasis can affect the tongue (geographic tongue-like lesions) and nails, the classic oral lesions are not described as **lacy linear patterns**. - Nail changes in psoriasis include **pitting, onycholysis, and oil spots**, not usually elongation of the nail fold beyond the nail bed. *Geographic tongue* - Geographic tongue presents as **irregular, depapillated red patches with white borders** that migrate over time. - It is a benign inflammatory condition of the tongue and is not associated with **nail changes** like elongated nail folds.

Q: A 26-year-old female patient presented with oral ulcers, sensitivity to light and rash over the malar area of the face sparing the nasolabial folds of both sides. Which of the following is most characteristic of this condition?

Butterfly rash sparing the nasolabial folds. ***Butterfly rash sparing the nasolabial folds*** - The patient's presentation with oral ulcers, sensitivity to light (photosensitivity), and a rash over the malar area **sparing the nasolabial folds** is highly characteristic of **Systemic Lupus Erythematosus (SLE)**, a condition where a butterfly rash is a hallmark. - This specific distribution of the malar rash is a key diagnostic feature differentiating it from other facial rashes. *Heliotrope rash on upper eyelid, bilateral hilar lymphadenopathy* - A **heliotrope rash** on the upper eyelids is characteristic of **dermatomyositis**, which also presents with muscle weakness, not typically oral ulcers or a malar rash. - **Bilateral hilar lymphadenopathy** is a classic finding in **sarcoidosis**, a granulomatous disease, not directly related to the patient's symptoms. *Port-wine stain, CNS malformations: seen in Sturge-Weber syndrome* - A **port-wine stain** (nevus flammeus) is a congenital capillary malformation, often on the face, and is a principal feature of **Sturge-Weber syndrome**, which involves CNS malformations and seizures. - This condition has no association with oral ulcers, photosensitivity, or the described malar rash. *Silvery scales or plaques: seen in psoriasis* - **Silvery scales or plaques** are the characteristic dermatological lesions of **psoriasis**, a chronic inflammatory skin condition. - Psoriasis typically presents with well-demarcated erythematous plaques and is not associated with oral ulcers, photosensitivity, or a lupus-specific malar rash.

Q: Match the following autoantibodies with their associated conditions: 1. BP180 a. Pemphigus vulgaris 2. Desmoglein 3 b. Bullous pemphigoid 3. Type VII collagen c. Epidermolysis bullosa acquisita

1-b, 2-a, 3-c. ***1-b, 2-a, 3-c*** - **BP180** is an autoantigen targeted in **bullous pemphigoid**, a subepidermal blistering disease. - **Desmoglein 3** is a key autoantigen in **pemphigus vulgaris**, a life-threatening intraepidermal blistering disorder. - **Type VII collagen** is involved in anchoring fibrils and is the target of autoantibodies in **epidermolysis bullosa acquisita**, causing chronic blistering. *1-a, 2-b, 3-c* - This option incorrectly associates **BP180 with pemphigus vulgaris** and **Desmoglein 3 with bullous pemphigoid**; their associations are reversed. - While Type VII collagen is correctly linked with epidermolysis bullosa acquisita, the other pairings are incorrect. *1-c, 2-a, 3-b* - This option incorrectly links **BP180 with epidermolysis bullosa acquisita** and **Type VII collagen with bullous pemphigoid**. - While Desmoglein 3 is correctly paired with pemphigus vulgaris, the other two associations are wrong, making this overall incorrect. *1-b, 2-c, 3-a* - This option incorrectly links **Desmoglein 3 with epidermolysis bullosa acquisita** and **Type VII collagen with pemphigus vulgaris**. - While BP180 is correctly associated with bullous pemphigoid, the other two associations are incorrect.

Question 1

A 32-year-old woman presents with multiple pruritic papules and vesicles on her elbows and knees. She reports a history of gluten sensitivity. Skin biopsy shows granular IgA deposits in dermal papillae. Which of the following is most likely to be elevated in this patient's serum?

Accepted Answer

Anti-tissue transglutaminase antibodies

Answer

Anti-DNA antibodies

Answer

Anti-type VII collagen antibodies

Answer

Anti-BP180 antibodies

Question 2

A 58-year-old woman presents with tense bullae on an erythematous base, primarily affecting her trunk and extremities. The lesions developed over the past 3 weeks. Nikolsky sign is negative. Skin biopsy shows subepidermal bullae with eosinophilic infiltrate. Direct immunofluorescence shows linear deposits of IgG and C3 at the basement membrane zone. Which of the following is the target antigen in this condition?

Accepted Answer

BP180/BP230

Answer

Type IV collagen

Answer

Type VII collagen

Answer

Desmoglein-3

Question 3

A skin biopsy shows acantholysis with intraepidermal blistering. Which immunofluorescence pattern would confirm pemphigus vulgaris?

Accepted Answer

Fishnet pattern of IgG

Answer

Linear IgA deposits

Answer

Granular IgG deposits

Answer

Linear C3 deposits

Question 4

Periungual telangiectasias are pathognomonic signs of the following except:

Accepted Answer

Polyarteritis nodosa

Answer

Systemic sclerosis

Answer

Dermatomyositis

Answer

Lupus erythematosus

Question 5

Acute febrile neutrophilic dermatosis is seen in-

Accepted Answer

Sweet syndrome

Answer

Behcet's syndrome

Answer

Haberman syndrome

Answer

Kasabach-Merritt syndrome

Question 6

A patient with typical cutaneous lesions, slightly elevated red or purple macules often covered by gray or yellow adherent scales. Forceful removal of the scale reveals numerous ‘carpet tack’ extensions. The lesion is:

Accepted Answer

DLE

Answer

Scleroderma

Answer

SLE

Answer

Lichen planus

Question 7

A young female presented with lacy linear lesions on tongue for a month with elongation of nail fold beyond the nail bed. What is the diagnosis –

Accepted Answer

Lichen planus

Answer

Candidiasis

Answer

Psoriasis

Answer

Geographic tongue

Question 8

A 26-year-old female patient presented with oral ulcers, sensitivity to light and rash over the malar area of the face sparing the nasolabial folds of both sides. Which of the following is most characteristic of this condition?

Accepted Answer

Butterfly rash sparing the nasolabial folds

Answer

Heliotrope rash on upper eyelid, bilateral hilar lymphadenopathy

Answer

Port-wine stain with CNS malformations

Answer

Silvery scales or plaques

Question 9

A 70-year-old woman with bullous pemphigoid develops severe disease flare while tapering prednisone from 40mg daily. Current dose is 20mg daily. She has diabetes with HbA1c 8.5% and osteoporosis. Most appropriate next step is:

Accepted Answer

Add rituximab

Answer

Start doxycycline and niacinamide

Answer

Add azathioprine

Answer

Increase prednisone back to 40mg

Question 10

Match the following autoantibodies with their associated conditions:
1. BP180 a. Pemphigus vulgaris
2. Desmoglein 3 b. Bullous pemphigoid
3. Type VII collagen c. Epidermolysis bullosa acquisita

Accepted Answer

1-b, 2-a, 3-c

Answer

1-a, 2-b, 3-c

Answer

1-c, 2-a, 3-b

Answer

1-b, 2-c, 3-a

Autoimmune Skin Diseases — MCQs

Autoimmune Skin Diseases — MCQs

On this page

Practice by Chapter

Want unlimited practice?