Autoimmune Skin Diseases Practice Questions

Q: A woman presents with pruritic rash on the elbows, buttocks with recent diagnosis of gluten sensitive enteropathy. On immunofluorescence IgA deposition is seen as shown in the image. What is the most likely diagnosis?

Dermatitis herpetiformis. ***Dermatitis herpetiformis*** - The combination of severely **pruritic, grouped vesicles (herpetiform)** on extensor surfaces (elbows, buttocks) and underlying **gluten-sensitive enteropathy** is pathognomonic. - The immunofluorescence image demonstrates characteristic **granular IgA deposition** specifically in the **dermal papillae**, which confirms the diagnosis. *Pemphigus vulgaris* - DIF typically shows a **"fishnet" pattern** of **IgG and C3** deposition in the **intercellular spaces** of the epidermis. - Clinically presents with **flaccid intraepidermal bullae** and extensive mucosal erosions, which is distinct from the patient's presentation. *Bullous pemphigoid* - DIF is characterized by **linear deposition of IgG and C3 along the basement membrane zone** (BMZ), not granular IgA in the dermal papillae. - Clinically, it presents with **tense bullae**, often in the elderly, and is not linked to gluten-sensitive enteropathy. *Psoriasis* - This condition is characterized by **erythematous plaques with silvery scales** (Koebner phenomenon is common) and is a papulosquamous disorder, not a bullous disease. - The histopathology involves acanthosis and Munro microabscesses, and it lacks the specific **IgA deposits** seen in the image.

Q: Identify the lesion:

Dermatomyositis. ***Dermatomyositis*** - The image shows **Gottron's papules** over the extensor surfaces of the elbows, which are characteristic of dermatomyositis. These are violaceous, erythematous, flat-topped papules. - While typically found on the **dorsum of the hands** over the MCP and IP joints, they can also occur on elbows, knees, and ankles. *Psoriasis* - Psoriasis typically presents with **well-demarcated erythematous plaques** covered with silvery scales, especially on extensor surfaces. - The lesions in the image lack the characteristic **silvery scaling** of psoriasis. *Dermatitis herpetiformis* - This condition presents with intensely **itchy, polymorphic lesions**, including vesicles, bullae, and excoriations, arranged in a symmetrical fashion, often on extensor surfaces. - The lesions in the image are papular and nodular, not exhibiting the characteristic **vesicular or bullous eruption** of dermatitis herpetiformis. *Erythema marginatum* - Erythema marginatum is a **transient, non-pruritic erythematous rash** with serpiginous borders and central clearing, typically seen in **acute rheumatic fever**. - The lesions in the image are fixed papules/nodules without the characteristic migrating or rapidly changing appearance of erythema marginatum.

Q: These lesions are seen in which of the following?

Erythema nodosum. ***Erythema nodosum*** - The image displays typical **erythematous, tender nodules**, consistent with **erythema nodosum**. - These lesions usually appear on the **shins** but can be found elsewhere, representing a form of **panniculitis**. *Erythema infectiosum* - Characterized by a distinctive **"slapped cheek" rash** on the face and a lacy, reticular rash on the body, which is not seen here. - It is caused by **parvovirus B19** and primarily affects children. *Erythema induratum* - Presents as chronic, recurring **tender nodules and plaques**, typically on the **calves**, often associated with tuberculosis. - While it is a form of panniculitis, its specific morphology and association with TB differ from the common presentation of erythema nodosum. *Erythema multiforme* - Known for its characteristic **target lesions** with multiple rings and a central blister or crust, often symmetrically distributed. - It is commonly triggered by infections (e.g., herpes simplex virus) or drugs, presenting with a different morphology from the image.

Q: The image is diagnostic of?

Fox Fordyce disease. ***Fox-Fordyce disease*** - The image shows **multiple, firm, dome-shaped papules** primarily affecting the axillary and genitofemoral regions. - These lesions often arise from **blocked apocrine sweat ducts** and are typically intensely pruritic, a common presentation of Fox-Fordyce disease. *Acne fulminans* - This condition is characterized by an **acute onset of severe, nodulocystic acne lesions** with ulceration, hemorrhagic crusts, and systemic symptoms like fever and arthritis. - The image does not display the extensive inflammation, ulceration, or typical clinical features of acne fulminans. *Acne conglobata* - Acne conglobata presents with interconnected **comedones, cysts, abscesses, and sinus tracts**, often leading to significant scarring. - While it can be severe, the individual lesions pictured are less inflammatory and interconnected than typically seen in acne conglobata. *Hidradenitis Suppurativa* - Hidradenitis suppurativa is characterized by **recurrent painful nodules, abscesses, and sinus tracts**, predominantly in intertriginous areas (axillae, groin, gluteal folds). - Although the location is similar to the image, the lesions in hidradenitis suppurativa are typically larger, more inflamed, and often result in extensive scarring and drainage, which is not the primary feature here.

Q: The following lesion appears on the leg of a patient of ulcerative colitis. All are useful in management except:

Sulfapyridine. ***Sulfapyridine*** - The image shows **pyoderma gangrenosum**, a painful ulcerative skin condition often associated with inflammatory bowel disease like ulcerative colitis. Among the given options, **sulfapyridine** has the **least established role** in pyoderma gangrenosum management. - **Sulfapyridine** is an inactive component of **sulfasalazine** and primarily acts as an **antibacterial agent**. While sulfasalazine has been reported in some PG cases, sulfapyridine alone is not a recognized treatment for the inflammatory, non-infectious nature of pyoderma gangrenosum. - Unlike the other options which have well-established roles, sulfapyridine lacks strong evidence for efficacy in PG. *Steroids* - **Corticosteroids** (oral or topical) are the **first-line treatment** for pyoderma gangrenosum due to their potent anti-inflammatory and immunosuppressive effects. - They help to reduce the inflammation and promote healing of the painful ulcers. *Procto-colectomy* - In cases of severe, refractory pyoderma gangrenosum associated with ulcerative colitis, **colectomy** can be a **definitive treatment** as it removes the underlying inflammatory trigger. - This surgical intervention is considered when medical therapies are unsuccessful or when the colonic disease itself necessitates surgery. *Infliximab* - **Infliximab**, a **TNF-alpha inhibitor**, is a biologic agent effective in treating both ulcerative colitis and pyoderma gangrenosum. - It is used in cases that are refractory to steroids or when patients cannot tolerate steroid therapy.

Q: The following lesion appears on the cheek of a patient of ulcerative colitis. It subsided with potassium iodide treatment. What is the diagnosis?

Pyoderma gangrenosum. ***Pyoderma gangrenosum*** - Pyoderma gangrenosum is a **neutrophilic dermatosis** strongly associated with **inflammatory bowel disease** (particularly ulcerative colitis in 50% of cases). - Presents as rapidly progressive, painful **ulcerative lesions** with characteristic **violaceous, undermined borders**. - While classically found on the **lower extremities**, it can occur at any site including the face (rare). - **Standard treatment** includes systemic corticosteroids, cyclosporine, and biologics (anti-TNF agents). - Note: Potassium iodide is **not a standard therapy** for pyoderma gangrenosum; this represents an unusual treatment response if documented in this case. *Erythema nodosum* - Presents as **tender, erythematous nodules** (panniculitis) typically on the **anterior shins**. - Can be associated with inflammatory bowel disease as an extraintestinal manifestation. - Rarely presents on the face; lesions are **non-ulcerative**. - May respond to **potassium iodide** in some cases, but the lesion morphology (ulcerative) does not fit. *Erythema marginatum* - A rare cutaneous manifestation of **acute rheumatic fever**. - Presents as **pink or red annular lesions** with central clearing and serpiginous borders on trunk and proximal extremities. - **Not associated** with inflammatory bowel disease. - Does not present as ulcerative lesions. *Sweet syndrome* - **Acute febrile neutrophilic dermatosis** presenting with **tender, erythematous plaques and nodules**. - Can be associated with inflammatory bowel disease. - Typically affects the **face, neck, and upper extremities**. - Lesions are characteristically **non-ulcerative** (unlike pyoderma gangrenosum). - Does not respond to potassium iodide; treatment is systemic corticosteroids.

Q: The following image shows:

Hypertrophic pulmonary osteoarthropathy. ***Hypertrophic pulmonary osteoarthropathy*** - The image displays prominent **clubbing of the fingers** and **swollen, painful joints**, which are classic signs of hypertrophic pulmonary osteoarthropathy (HPO). - HPO is characterized by **periostosis** (new bone formation) of the long bones, especially in the distal extremities, often secondary to chronic pulmonary or cardiac diseases. *Sausage digits* - Sausage digits (dactylitis) are characterized by **diffuse swelling of an entire digit**. While the fingers appear swollen, the specific, uniform swelling characteristic of dactylitis is not overtly present or is overshadowed by other features. - This condition is typically associated with **psoriatic arthritis** or **spondyloarthritis**. *Heberden's nodes* - Heberden's nodes are **bony enlargements** of the **distal interphalangeal (DIP) joints**, characteristic of osteoarthritis. - The image shows more widespread swelling and less distinct bony nodes, and the swelling extends beyond just the DIP joints. *Subungual fibroma* - Subungual fibromas are **benign tumors** that occur **underneath the nail**, typically causing a bulge or distortion of the nail plate. - While there might be some nail changes, the predominant features in the image are the generalized swelling and clubbing of the digits, not isolated subungual growths.

Q: All are true about the lesions shown except:

Non pruritic. ***Non pruritic*** - The lesions shown are characteristic of **Lichen Planus**, which is classically described as intensely **pruritic**. - **Pruritus** is a hallmark symptom of lichen planus, often preceding the appearance of the rash. - Since the question asks "all are true **EXCEPT**", this is the **correct answer** as it is the FALSE statement. *Violaceous lesions* - **Lichen Planus** typically presents with **violaceous**, polygonal, planar, pruritic papules and plaques. - The image indeed shows lesions with a purplish or violaceous hue. - This is a TRUE statement about lichen planus. *Wickham Striae* - **Wickham Striae** are fine, white, lacy patterns seen on the surface of papules in lichen planus, especially when examined with a dermatoscope or magnification. - These are a distinctive and diagnostic feature of **lichen planus**, indicating areas of hypertrophic stratum granulosum. - This is a TRUE statement about lichen planus. *Saw tooth appearance of rete ridges* - On **histopathology**, lichen planus is characterized by a **"sawtooth" appearance of the rete ridges** due to irregular epidermal proliferation and a dense, band-like lymphocytic infiltrate at the dermo-epidermal junction. - This is a key microscopic feature for diagnosing **lichen planus**. - This is a TRUE statement about lichen planus.

Q: All are true about the lesion shown below except:

Seen in chronic renal failure. The image shows **Erythema Multiforme (EM)**, characterized by target (iris) lesions with a predilection for acral areas. ***Correct Answer: Seen in chronic renal failure*** - Erythema Multiforme is **NOT associated with chronic renal failure** - EM is a **hypersensitivity reaction** most commonly triggered by infections (especially HSV, Mycoplasma) or drugs - Chronic renal failure is associated with other dermatologic conditions like **pseudoporphyria**, **acquired perforating dermatosis**, and **calciphylaxis**, but NOT Erythema Multiforme - This is the FALSE statement, making it the correct answer to this EXCEPT question *Incorrect: Target lesions* - **Target (iris) lesions are PATHOGNOMONIC for Erythema Multiforme** - These appear as concentric zones of color change with a dusky central area, surrounded by pale edema, and an outer erythematous ring - The "three-zone" target lesion is the hallmark feature that distinguishes EM from other conditions - This statement is TRUE, so it is NOT the answer to this EXCEPT question *Incorrect: Crops heal with Hyperpigmentation* - **TRUE** - EM lesions typically heal with post-inflammatory hyperpigmentation, especially in darker skin types - The lesions appear in crops over 3-5 days and resolve over 1-2 weeks - No scarring occurs, but pigmentary changes may persist for weeks to months - This statement is TRUE, so it is NOT the answer to this EXCEPT question *Incorrect: Predominant on acral and face area* - **TRUE** - EM has a characteristic **acral distribution** - Lesions favor the **extensor surfaces of distal extremities** (dorsum of hands, feet, elbows, knees) - **Palms, soles, and face** are commonly involved - This acral predominance distinguishes EM from other erythematous eruptions - This statement is TRUE, so it is NOT the answer to this EXCEPT question

Q: The image shows:

Allergic shiners. ***Allergic shiners*** - The image clearly displays **dark, discolored patches under the eyes**, which are characteristic of allergic shiners. - These are caused by **venous congestion** and extravasation of deoxygenated blood secondary to inflammation or chronic nasal congestion, often associated with allergies. *Allergic salute* - The allergic salute is a **physical maneuver**, where a person rubs their nose upwards with their palm, not a visible sign in this static image. - It results in a **transverse crease across the nasal bridge** over time, which is not what the image shows. *Allergic line* - An "allergic line" or "allergic crease" typically refers to the **transverse nasal crease** caused by the allergic salute, which is not depicted here. - There is no such specific medical term as an "allergic line" referring to the suborbital discoloration shown. *Dennis Morgan's fold* - A Dennis-Morgan fold (more commonly **Dennie-Morgan fold**) is an **extra fold or crease in the skin below the lower eyelid**, often associated with allergic conditions like atopic dermatitis. - While related to allergies, the term more precisely describes this specific **skin fold**, and the image predominantly shows the diffuse dark discoloration, which is the defining characteristic of allergic shiners.

Question 1

A woman presents with pruritic rash on the elbows, buttocks with recent diagnosis of gluten sensitive enteropathy. On immunofluorescence IgA deposition is seen as shown in the image. What is the most likely diagnosis?

Accepted Answer

Dermatitis herpetiformis

Answer

Psoriasis

Answer

Bullous pemphigoid

Answer

Pemphigus vulgaris

Question 2

Identify the lesion:

Accepted Answer

Dermatomyositis

Answer

Psoriasis

Answer

Dermatitis herpetiformis

Answer

Erythema marginatum

Question 3

These lesions are seen in which of the following?

Accepted Answer

Erythema nodosum

Answer

Erythema infectiosum

Answer

Erythema induratum

Answer

Erythema multiforme

Question 4

The image is diagnostic of?

Accepted Answer

Fox Fordyce disease

Answer

Acne fulminans

Answer

Acne conglobata

Answer

Hidradenitis Suppurativa

Question 5

The following lesion appears on the leg of a patient of ulcerative colitis. All are useful in management except:

Accepted Answer

Sulfapyridine

Answer

Steroids

Answer

Procto-colectomy

Answer

Infliximab

Question 6

The following lesion appears on the cheek of a patient of ulcerative colitis. It subsided with potassium iodide treatment. What is the diagnosis?

Accepted Answer

Pyoderma gangrenosum

Answer

Erythema nodosum

Answer

Erythema marginatum

Answer

Sweet syndrome

Question 7

The following image shows:

Accepted Answer

Hypertrophic pulmonary osteoarthropathy

Answer

Sausage digits

Answer

Heberden's nodes

Answer

Subungual fibroma

Question 8

All are true about the lesions shown except:

Accepted Answer

Non pruritic

Answer

Violaceous lesions

Answer

Wickham Striae

Answer

Saw tooth appearance of rete ridges

Question 9

All are true about the lesion shown below except:

Accepted Answer

Seen in chronic renal failure

Answer

Target lesions

Answer

Crops heal with Hyper-pigmentation

Answer

Predominant on acral and face area

Question 10

The image shows:

Accepted Answer

Allergic shiners

Answer

Allergic salute

Answer

Allergic line

Answer

Dennie-Morgan fold

Autoimmune Skin Diseases — MCQs

Autoimmune Skin Diseases — MCQs

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