Dermatitis Herpetiformis Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Dermatitis Herpetiformis. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Dermatitis Herpetiformis Indian Medical PG Question 1: Identify the diagnosis based on the dermatology immunofluorescence (IF) image provided.
- A. Pemphigus vulgaris
- B. Pemphigus foliaceus
- C. Bullous pemphigoid
- D. Dermatitis herpetiformis (Correct Answer)
Dermatitis Herpetiformis Explanation: ***Dermatitis herpetiformis***
- The immunofluorescence image shows **granular IgA deposits** at the **dermal papillae region**, which is characteristic of dermatitis herpetiformis.
- This condition is strongly associated with **celiac disease** and presents with intensely pruritic papules and vesicles.
*Pemphigus vulgaris*
- Immunofluorescence in pemphigus vulgaris typically shows a **fishnet pattern** of IgG deposits throughout the **epidermis**, reflecting antibodies against desmoglein 3 and 1.
- This pattern is an intercellular deposition, not granular at the dermal papillae.
*Pemphigus foliaceus*
- Similar to pemphigus vulgaris, pemphigus foliaceus also exhibits **intercellular IgG deposits** in the epidermis, but it is usually more superficial, targeting desmoglein 1.
- The image does not show this intercellular epidermal staining.
*Bullous pemphigoid*
- Bullous pemphigoid is characterized by **linear IgG and C3 deposits along the dermal-epidermal junction** (basement membrane zone).
- The image distinctly shows granular IgA, not linear IgG/C3, and specifically in the dermal papillae.
Dermatitis Herpetiformis Indian Medical PG Question 2: Dapsone is NOT used in:
- A. Dermatitis herpetiformis
- B. Alopecia areata (Correct Answer)
- C. Pneumocystis jirovecii pneumonia prophylaxis
- D. Leprosy
Dermatitis Herpetiformis Explanation: ***Alopecia areata***
- **Dapsone** is an **antibiotic** with anti-inflammatory and immunomodulatory properties and is not indicated for the treatment of **alopecia areata**.
- Treatment for **alopecia areata** typically involves **corticosteroids** (topical, intralesional, or systemic) or other immunosuppressants.
*Dermatitis herpetiformis*
- **Dapsone** is the **first-line treatment** for **dermatitis herpetiformis** due to its rapid antipruritic effect, often providing relief within 24-48 hours.
- It works by reducing the inflammation and formation of the characteristic **subepidermal blisters** seen in this condition.
*Pneumocystis jirovecii pneumonia prophylaxis*
- **Dapsone** is an effective **alternative agent** for prophylaxis against **Pneumocystis jirovecii pneumonia (PCP)**, especially in patients who cannot tolerate trimethoprim-sulfamethoxazole.
- It is often used in combination with **pyrimethamine** for toxoplasmosis prophylaxis in HIV-infected patients.
*Leprosy*
- **Dapsone** is a crucial component of **multidrug therapy (MDT)** for both paucibacillary and multibacillary forms of **leprosy**.
- It acts as a **bacteriostatic agent** against Mycobacterium leprae and has been a cornerstone of leprosy treatment for decades.
Dermatitis Herpetiformis Indian Medical PG Question 3: A patient presents with skin lesions and erosions on the buccal mucosa. The immunofluorescence image is shown. What is the most likely diagnosis?
- A. Bullous pemphigoid
- B. Pemphigus vulgaris (Correct Answer)
- C. Linear IgA disease
- D. Dermatitis herpetiformis
Dermatitis Herpetiformis Explanation: ***Pemphigus vulgaris***
- The combination of **flaccid blisters/erosions** on the skin and **buccal mucosal lesions** is characteristic of pemphigus vulgaris. The image showing **intercellular IgG deposits** (a "chicken wire" pattern) in the epidermis confirms the diagnosis on immunofluorescence.
- Pemphigus vulgaris is an **autoimmune blistering disease** caused by autoantibodies against **desmoglein 1 and 3**, leading to acantholysis (loss of cell adhesion) within the epidermis.
*Bullous pemphigoid*
- This condition typically presents with **tense bullae** that are less prone to rupture, and **mucosal involvement is rare**.
- Immunofluorescence in bullous pemphigoid shows **linear IgG and C3 deposits at the dermoepidermal junction**, not an intercellular epidermal pattern.
*Linear IgA disease*
- Characterized by **linear IgA deposition along the basement membrane zone** on direct immunofluorescence.
- Clinically, it presents with **blisters** that can be variable in appearance, but the pathognomonic immunofluorescence pattern is distinct.
*Dermatitis herpetiformis*
- Presents with very **pruritic vesicles and papules**, primarily on extensor surfaces, and is strongly associated with **celiac disease**.
- Direct immunofluorescence reveals **granular IgA deposits in the dermal papillae**, which is distinct from the intercellular IgG pattern seen here.
Dermatitis Herpetiformis Indian Medical PG Question 4: A child presents with grouped vesicles on an erythematous base on the buttocks. What is the most likely diagnosis?
- A. Bullous impetigo
- B. Dermatitis herpetiformis
- C. Pemphigus
- D. Herpes simplex (Correct Answer)
Dermatitis Herpetiformis Explanation: ***Herpes simplex***
- Herpes simplex virus (HSV) classically presents with **grouped vesicles on an erythematous base**, which perfectly matches this clinical presentation.
- In **children**, HSV commonly affects the **buttocks** through autoinoculation or direct contact, especially in the diaper area.
- The lesions are typically **painful and pruritic**, and may be preceded by tingling or burning sensation.
- Diagnosis is confirmed by **Tzanck smear** (multinucleated giant cells), **PCR**, or **viral culture**.
- Treatment includes **acyclovir** or other antivirals, especially for severe or recurrent cases.
*Dermatitis herpetiformis*
- While DH does present with intensely pruritic, grouped vesicles on an erythematous base, it is **extremely rare in children** and typically presents in **adults (3rd-4th decade)**.
- Classic sites include **extensor surfaces** (elbows, knees), scalp, and buttocks, but the pediatric presentation makes this diagnosis unlikely.
- It is strongly associated with **celiac disease** and responds to **gluten-free diet** and **dapsone**.
*Bullous impetigo*
- Bullous impetigo presents with **flaccid bullae** that rupture to form **honey-colored crusts**, not grouped vesicles.
- It is a **bacterial infection** caused by *Staphylococcus aureus* producing exfoliative toxin.
- Common in **young children**, particularly in warm, humid conditions.
*Pemphigus*
- Pemphigus is **extremely rare in children** and causes **fragile bullae** that easily rupture, leading to erosions.
- Typically affects **mucous membranes first** (oral cavity), then skin.
- It is an **autoimmune blistering disease** with antibodies against desmoglein, causing intraepidermal acantholysis.
Dermatitis Herpetiformis Indian Medical PG Question 5: Which of the following is NOT associated with erythema nodosum?
- A. Leprosy
- B. Tuberculosis
- C. Pemphigus vulgaris (Correct Answer)
- D. Sarcoidosis
Dermatitis Herpetiformis Explanation: ***Pemphigus vulgaris***
- Pemphigus vulgaris is an **autoimmune blistering disease** affecting the skin and mucous membranes, characterized by **flaccid bullae** that easily rupture.
- Its pathogenesis involves autoantibodies against **desmogleins 1 and 3**, components of desmosomes, and it does not typically manifest with subcutaneous nodules or inflammation seen in erythema nodosum.
*Leprosy*
- Leprosy, particularly its **lepromatous forms**, can cause immunologically mediated inflammatory reactions known as **erythema nodosum leprosum**.
- This presentation involves multiple tender, inflamed subcutaneous nodules, clinically and histologically resembling typical erythema nodosum.
*Tuberculosis*
- Tuberculosis is a well-known infectious cause of **erythema nodosum**, especially in young adults and children.
- The skin lesions often indicate a **hypersensitivity reaction** to the mycobacterial antigens.
*Sarcoidosis*
- Sarcoidosis is a systemic granulomatous disease, and **erythema nodosum** is a common **cutaneous manifestation**, particularly in acute sarcoidosis.
- When associated with bilateral hilar lymphadenopathy and arthralgia, it forms **Löfgren's syndrome**, a specific presentation of sarcoidosis.
Dermatitis Herpetiformis Indian Medical PG Question 6: A child presents with itchy lesions and diarrhea and has been advised to follow a gluten-free diet. What is the most likely etiology of this condition?
- A. Whipple's disease
- B. Crohn's disease
- C. Dermatitis herpetiformis
- D. Celiac disease (Correct Answer)
Dermatitis Herpetiformis Explanation: ***Celiac disease***
- **Celiac disease** is an autoimmune condition triggered by **gluten ingestion**, leading to small intestine damage and nutrient malabsorption.
- The combination of **itchy lesions** (dermatitis herpetiformis, a skin manifestation of celiac disease), **diarrhea**, and improvement on a **gluten-free diet** are highly characteristic.
- Since the question asks for the **underlying etiology**, celiac disease is the correct answer as it causes both the skin and GI manifestations.
*Whipple's disease*
- This is a rare systemic infection caused by the bacterium **Tropheryma whipplei**, presenting with **arthralgia, fever, malabsorption, and lymphadenopathy**.
- While it can cause diarrhea and malabsorption, it is not associated with itchy skin lesions and does not respond to a gluten-free diet.
*Crohn's disease*
- **Crohn's disease** is a type of inflammatory bowel disease affecting any part of the GI tract, causing **abdominal pain, diarrhea, and weight loss**.
- It is not associated with dermatitis herpetiformis and does not improve with a gluten-free diet (though some patients may have gluten sensitivity).
*Dermatitis herpetiformis*
- **Dermatitis herpetiformis** is the **cutaneous manifestation of celiac disease**, presenting as intensely itchy, vesicular lesions.
- While DH explains the itchy lesions in this case, it is a **symptom/manifestation**, not the underlying **etiology**—the root cause is celiac disease itself, which produces both the intestinal damage (diarrhea) and the skin manifestations (DH).
Dermatitis Herpetiformis Indian Medical PG Question 7: A child presents with grouped vesicles on an erythematous base on buttocks, knees and elbows. Diagnosis?
- A. Dermatitis herpetiformis (Correct Answer)
- B. Pemphigus
- C. Bullous impetigo
- D. Herpes simplex
Dermatitis Herpetiformis Explanation: ***Dermatitis herpetiformis***
- The classic presentation of **grouped vesicles on an erythematous base** over the **extensor surfaces** like the buttocks, knees, and elbows is characteristic of **dermatitis herpetiformis**.
- This condition is strongly associated with **celiac disease** and is caused by IgA deposition in the dermal papillae.
*Pemphigus*
- Pemphigus typically involves **flaccid bullae** that rupture easily, often presenting on the **mucous membranes** and skin, but not usually as grouped vesicles on an erythematous base.
- It is an **autoimmune blistering disease** caused by autoantibodies against desmoglein, leading to **intraepidermal blistering**.
*Bullous impetigo*
- Bullous impetigo is a **bacterial skin infection** characterized by **fragile, fluid-filled blisters** (bullae) that can rupture and leave a honey-colored crust, commonly caused by *Staphylococcus aureus.*
- While it presents with bullae, it does not typically show the characteristic **grouped vesicles on an erythematous base** seen in dermatitis herpetiformis.
*Herpes simplex*
- Herpes simplex infection causes **grouped vesicles** on an erythematous base, but these are typically found around the **oral (herpes labialis)** or **genital areas**.
- While the morphology is similar, the **distribution on the buttocks, knees, and elbows** in a child points away from herpes simplex as the primary diagnosis.
Dermatitis Herpetiformis Indian Medical PG Question 8: A 26-year-old girl at 31 weeks' gestation complains of a 4-week history of a pustular eruption that initially developed on the periumbilical skin and subsequently spread to involve the breasts, back, flexures, and proximal limbs, accompanied by cutaneous pain, fever, and malaise. On examination, the lesions were found to be pustules arranged in concentric rings, while on the breasts, there was coalescence of pustules forming lakes of pus. What is the treatment of choice in this case?
- A. Corticosteroids (Correct Answer)
- B. Methotrexate
- C. Topical itraconazole
- D. Third generation cephalosporins
Dermatitis Herpetiformis Explanation: ***Corticosteroids***
- The constellation of **pustular eruption** with **concentric rings**, especially in pregnancy, along with systemic symptoms like fever and malaise, is highly suggestive of **Pustular Psoriasis of Pregnancy (PPP)**, also known as **Impetigo Herpetiformis**.
- **Systemic corticosteroids** (prednisolone) are the **first-line treatment** for this rare but severe dermatosis in pregnancy, aimed at controlling inflammation and preventing maternal and fetal complications.
*Methotrexate*
- **Methotrexate** is an **anti-metabolite** and **immunosuppressant** that is **teratogenic** and absolutely **contraindicated in pregnancy** due to its potential to cause severe birth defects and miscarriages.
- While it can be used for severe psoriasis in non-pregnant individuals, its use in this pregnant patient is inappropriate and dangerous.
*Topical itraconazole*
- **Itraconazole** is an **antifungal medication** used to treat fungal infections. While typically used systemically, topical formulations exist for localized fungal infections.
- The clinical presentation of widespread pustules arranged in **concentric rings** with systemic symptoms and **"lakes of pus"** in a pregnant woman is pathognomonic for **Impetigo Herpetiformis**, not a fungal infection, making this treatment inappropriate.
*Third generation cephalosporins*
- **Third-generation cephalosporins** are **antibiotics** primarily used to treat bacterial infections.
- The distinctive pattern of **pustules in concentric rings**, the periumbilical onset, and progression to form **lakes of pus** in a pregnant woman represents an **inflammatory dermatosis** (Impetigo Herpetiformis), not a primary bacterial infection requiring antibiotics.
Dermatitis Herpetiformis Indian Medical PG Question 9: Patient presents with pruritus of the interdigital spaces of the left hand as shown in the image. Identify the condition.
- A. Sarcoptes scabiei (Correct Answer)
- B. Dermatitis herpetiformis
- C. Xerotic dermatitis
- D. Erythema multiforme
Dermatitis Herpetiformis Explanation: ***Sarcoptes scabiei***
- The image shows **papules and excoriations** in the **interdigital spaces**, a classic presentation of **scabies**. Patients typically experience **intense pruritus**, especially at night.
- The presence of **burrows**, which are linear or serpiginous tracks, further supports this diagnosis, as these are created by the female mite tunneling into the epidermis.
*Dermatitis herpetiformis*
- This condition is characterized by **intensely pruritic, symmetrically grouped vesicles and bullae** on extensor surfaces, such as elbows, knees, and buttocks, not primarily interdigital spaces.
- It is strongly associated with **celiac disease** and typically responds to a gluten-free diet and dapsone.
*Xerotic dermatitis*
- **Xerotic dermatitis**, also known as **eczema craquelé** or **winter itch**, is characterized by **dry, fissured skin** that resembles cracked porcelain, often exacerbated by dry weather.
- While it causes pruritus, it does not typically present with the papules and burrows seen in scabies, nor is it confined to interdigital spaces in this manner.
*Erythema multiforme*
- **Erythema multiforme** is an acute, self-limiting inflammatory skin condition characterized by **target lesions** (concentric rings of erythema and edema) and often involves mucous membranes.
- It is often triggered by infections (e.g., herpes simplex virus) or drugs and does not primarily present with pruritic papules in interdigital areas.
Dermatitis Herpetiformis Indian Medical PG Question 10: A child presents with grouped vesicles on an erythematous base on buttocks, knees and elbows. Diagnosis?
- A. Bullous impetigo
- B. Herpes simplex
- C. Pemphigus
- D. Dermatitis herpetiformis (Correct Answer)
Dermatitis Herpetiformis Explanation: ***Dermatitis herpetiformis***
- This condition presents with **grouped vesicles on an erythematous base**, characteristically affecting the **extensor surfaces** such as the buttocks, knees, and elbows.
- It is an **autoimmune blistering disease** strongly associated with **celiac disease**, making treatment with a **gluten-free diet** essential.
*Bullous impetigo*
- Characterized by **flaccid bullae** that rupture and leave a honey-colored crust, primarily caused by **Staphylococcus aureus**.
- Typically not associated with an erythematous base or the specific distribution seen in this case.
*Herpes simplex*
- Causes **grouped vesicles** on an erythematous base, but usually in a **localized distribution** (e.g., oral or genital) and often preceded by prodromal symptoms like tingling.
- While it can cause grouped vesicles, the widespread distribution on buttocks, knees, and elbows is atypical.
*Pemphigus*
- Pemphigus (e.g., Pemphigus vulgaris) involves **flaccid bullae** and often affects mucous membranes, with a positive **Nikolsky sign**.
- It is typically seen in adults and less commonly presents as grouped vesicles on specific extensor surfaces in children.
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