Autoimmune Skin Diseases Practice Questions

Q: Histological appearance of scleroderma includes all except?

Extensive fibrosis of upper 1/3 of the dermis. **Explanation:** The hallmark of **Scleroderma (Systemic Sclerosis)** is the excessive deposition of collagen throughout the dermis. However, the fibrosis is not limited to the upper 1/3; instead, it typically involves the **entire thickness of the dermis** and often extends into the subcutaneous fat. * **Why Option A is the correct answer:** In scleroderma, fibrosis is **pan-dermal**. The collagen bundles become thick, packed, and oriented parallel to the epidermis. Restricting the description to only the "upper 1/3" is histologically inaccurate as the disease process characteristically involves the deep dermis and leads to the loss of the dermo-hypodermal interface. * **Why other options are incorrect:** * **Decreased adnexal structures (B):** As collagen bundles expand and pack tightly, they "choke" or replace normal skin structures. This leads to the atrophy and eventual disappearance of hair follicles and sweat glands. * **Homogenization of collagen (C):** Under the microscope, the collagen bundles lose their distinct outlines and appear as a solid, eosinophilic (pink), glassy mass. * **Increased dermal thickness (D):** The massive deposition of Type I and Type III collagen significantly increases the overall depth of the dermal layer, which clinically manifests as skin tightening and induration. **NEET-PG High-Yield Pearls:** 1. **Square-off Sign:** On biopsy, the specimen often appears rectangular or "squared-off" because the tissue is so rigid it does not curl. 2. **Entrapment of Eccrine Glands:** A classic sign where sweat glands appear "trapped" in the middle of dense dermal collagen rather than sitting at the dermo-hypodermal junction. 3. **CD34+ Fibroblasts:** There is a characteristic **loss** of CD34+ dendritic interstitial cells in the affected dermis. 4. **Clinical Triad:** Vascular injury (Raynaud’s), Autoimmunity (ANA, Scl-70, Anti-centromere), and Progressive Fibrosis.

Q: In which condition is mucocutaneous candidiasis an important clinical feature?

Autoimmune hypoparathyroidism. **Explanation:** The correct answer is **Autoimmune hypoparathyroidism**. This condition is a hallmark component of **Autoimmune Polyendocrine Syndrome Type 1 (APS-1)**, also known as **APECED** (Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy). **1. Why Autoimmune Hypoparathyroidism is Correct:** APS-1 is caused by a mutation in the **AIRE (Autoimmune Regulator) gene**. The classic clinical triad includes: * **Chronic Mucocutaneous Candidiasis (CMC):** Usually the first sign, appearing in early childhood. * **Autoimmune Hypoparathyroidism:** The most common endocrine manifestation. * **Addison’s Disease:** Typically develops later. The presence of CMC in this context is due to the production of autoantibodies against Th17 cytokines (IL-17 and IL-22), which are essential for fungal mucosal immunity. **2. Why Other Options are Incorrect:** * **DiGeorge Syndrome:** While it involves hypocalcemia and T-cell deficiency (which can lead to infections), the classic triad involves thymic aplasia, cardiac defects, and cleft palate. It is not primarily defined by the specific CMC-hypoparathyroidism association seen in APS-1. * **Pseudohypoparathyroidism:** This is a genetic resistance to PTH (end-organ resistance). It is characterized by Albright’s Hereditary Osteodystrophy (short stature, round face, short 4th/5th metacarpals) but does not involve autoimmune candidiasis. * **Post-surgical Hypoparathyroidism:** This is an acquired mechanical complication (e.g., after thyroidectomy) and lacks any autoimmune or immunological component. **High-Yield Clinical Pearls for NEET-PG:** * **APS-1 Triad:** Candidiasis + Hypoparathyroidism + Addison’s Disease. * **Inheritance:** Autosomal Recessive (AIRE gene mutation on Chromosome 21). * **Dermatological Clue:** CMC in APS-1 often presents as persistent oral thrush, nail dystrophy, or angular cheilitis that is refractory to standard treatment.

Q: Which of the following is true about the chickenpox rash?

Pleomorphic. **Explanation:** The characteristic feature of the chickenpox (Varicella-Zoster Virus) rash is its **pleomorphic** nature. 1. **Why Pleomorphic is Correct:** Pleomorphism refers to the presence of lesions in **different stages of development** (macules, papules, vesicles, and crusts) simultaneously in the same anatomical area. This occurs because the rash appears in successive crops over 3–5 days. The classic vesicle is described as a **"dewdrop on a rose petal"** (clear vesicle on an erythematous base). 2. **Analysis of Incorrect Options:** * **Polymorphic:** While often used interchangeably in common parlance, in strict dermatological terms for NEET-PG, "pleomorphic" is the specific descriptor for the temporal evolution of chickenpox lesions. * **Centripetal:** This describes the **distribution**, not the morphology. The chickenpox rash is centripetal (starts on the trunk and spreads to the face and extremities), but the question asks for a defining characteristic of the rash itself. * **Cytoplasmic inclusions:** Varicella-Zoster Virus (a DNA herpesvirus) produces **intranuclear** eosinophilic inclusions (Cowdry type A), not cytoplasmic ones. Cytoplasmic inclusions are characteristic of Poxviruses (e.g., Molluscum bodies). **High-Yield Clinical Pearls for NEET-PG:** * **Tzanck Smear:** Shows **multinucleated giant cells** and acantholytic cells (common to HSV and VZV). * **Distribution:** Rapid progression from trunk → face → extremities (centripetal). Palms and soles are usually spared. * **Incubation Period:** 10–21 days. * **Infectivity:** From 1–2 days before the rash appears until all lesions have crusted over.

Q: Gottron papules are pathognomonic for which condition?

Dermatomyositis. **Explanation:** **1. Why Dermatomyositis is Correct:** Gottron papules are considered **pathognomonic** (specifically diagnostic) for Dermatomyositis. They are characterized by symmetric, violaceous (purplish), flat-topped papules or plaques found over the dorsal aspects of the interphalangeal and metacarpophalangeal joints. The underlying mechanism involves interface dermatitis, leading to inflammation at the dermo-epidermal junction. **2. Why Other Options are Incorrect:** * **Inclusion body myositis (IBM):** While it is an inflammatory myopathy, it typically lacks the classic cutaneous hallmarks of dermatomyositis. It presents with insidious, asymmetric muscle weakness, particularly affecting the finger flexors and quadriceps. * **Polymyositis:** This is a systemic inflammatory myopathy that shares similar muscle involvement with dermatomyositis but **lacks the characteristic skin rashes** (Gottron papules, Heliotrope rash). * **Discoid lupus erythematosus (DLE):** DLE presents with well-demarcated, erythematous, scaly plaques that lead to scarring and atrophy. Crucially, DLE lesions on the hands typically occur in the **inter-articular** areas (between the joints), whereas Gottron papules occur directly **over** the joints. **3. NEET-PG High-Yield Clinical Pearls:** * **Heliotrope Rash:** Violaceous edema of the upper eyelids; another hallmark of Dermatomyositis. * **Gottron Sign:** Macular erythema (not papules) over the knuckles, elbows, or knees. * **Shawl Sign/V-Sign:** Photosensitive erythema over the back/shoulders or upper chest. * **Mechanic’s Hands:** Hyperkeratosis and fissuring of the palms and lateral fingers (associated with **Anti-Jo-1** antibodies/Antisynthetase syndrome). * **Malignancy Link:** Dermatomyositis in adults is frequently a **paraneoplastic syndrome**; always screen for underlying internal malignancies (e.g., ovarian, lung, GI).

Q: A 40-year-old woman presented with an 8-month history of erythema and swelling of the periorbital region, papules and plaques on the dorsolateral aspect of forearms and knuckles, and ragged cuticles. There was no muscle weakness. What is the most likely diagnosis?

Dermatomyositis. **Explanation:** The clinical presentation is classic for **Dermatomyositis (DM)**. The diagnosis is based on the presence of pathognomonic cutaneous markers: 1. **Heliotrope Rash:** Erythema and edema of the periorbital region. 2. **Gottron’s Papules:** Violaceous papules and plaques over the knuckles (MCP, PIP, DIP joints) and dorsolateral forearms. 3. **Samitz’s Sign:** Ragged cuticles and periungual telangiectasia. Notably, the absence of muscle weakness suggests **Amyopathic Dermatomyositis**, a variant where characteristic skin lesions occur without clinical or laboratory evidence of myositis for at least 6 months. **Why other options are incorrect:** * **SLE:** While it causes malar rashes, it typically **spares the nasolabial folds** and involves the interjoint areas of the fingers rather than the knuckles (Gottron’s). * **Systemic Sclerosis:** Characterized by skin tightening (sclerodactyly), Raynaud’s phenomenon, and "beaked nose" facies, rather than inflammatory periorbital edema or Gottron’s papules. * **Mixed Connective Tissue Disorder (MCTD):** Usually presents with overlapping features of SLE, Scleroderma, and Polymyositis, often with high titers of **Anti-U1 RNP** antibodies. **High-Yield Clinical Pearls for NEET-PG:** * **Pathognomonic signs:** Gottron’s papules and Heliotrope rash. * **Shawl sign:** Erythema over the upper back and shoulders. * **V-sign:** Erythema over the anterior neck and upper chest. * **Mechanic’s hands:** Hyperkeratotic, fissured skin on the lateral aspects of fingers (associated with **Anti-Jo-1** antibodies and interstitial lung disease). * **Malignancy:** Dermatomyositis in adults is associated with an increased risk of internal malignancies (Ovarian, Lung, Gastric).

Q: Which of the following statements is true regarding this skin disease?

All of the above.. ***All of the above*** - **Psoriasis** is associated with **cardiovascular comorbidities**, **psoriatic arthritis**, and **pruritus**, making all three statements correct. - This **chronic inflammatory skin disease** has systemic manifestations beyond skin involvement, affecting multiple organ systems. *Can cause premature coronary artery disease* - **Psoriasis** is associated with increased risk of **myocardial infarction** and **cardiovascular mortality** due to chronic systemic inflammation. - Patients with severe psoriasis have a **50% higher risk** of cardiovascular events compared to the general population. *Can cause arthritis* - **Psoriatic arthritis** occurs in approximately **30% of psoriasis patients**, presenting as a **seronegative spondyloarthropathy**. - It can affect **peripheral joints**, **spine**, and cause **dactylitis** (sausage-shaped fingers) and **enthesitis**. *Itching can be present* - **Pruritus** is reported in **70-90% of psoriasis patients** and significantly impacts quality of life. - The itching can be **severe** and is often associated with **stress** and **sleep disturbances**.

Q: What is the earliest presenting feature of tuberous sclerosis?

Ash leaf spot. **Explanation:** **Tuberous Sclerosis Complex (TSC)** is an autosomal dominant neurocutaneous syndrome characterized by the development of benign tumors (hamartomas) in multiple organs. **Why Ash Leaf Spot is correct:** The **Ash leaf spot** (hypomelanotic macule) is the **earliest clinical sign** of Tuberous Sclerosis. These macules are often present at birth or appear in early infancy (usually before age 2). They are best visualized using a **Wood’s lamp**, which highlights the contrast between the hypopigmented area and normal skin. At least three such macules are required to meet the major diagnostic criteria. **Analysis of Incorrect Options:** * **Facial Angiofibromas (Adenoma Sebaceum):** These typically appear later in childhood, usually between **2 to 5 years of age**. They are malar distributions of pink-to-red papules. * **Shagreen Patch:** These are connective tissue nevi (leathery plaques) usually found on the lower back. They typically appear between **2 to 6 years of age**. * **Gingival Fibroma:** These are oral manifestations that generally appear in **late childhood or adolescence**, much later than the initial cutaneous markers. **NEET-PG High-Yield Pearls:** * **Vogt’s Triad:** Epilepsy, Mental Retardation, and Adenoma Sebaceum (only seen in ~30% of patients). * **Confetti Lesions:** Multiple tiny hypopigmented macules; these are highly specific for TSC. * **Koenen’s Tumor:** Periungual fibromas appearing around puberty; they are a major diagnostic criterion. * **Genetics:** Mutation in **TSC1 (Hamartin)** on chromosome 9 or **TSC2 (Tuberin)** on chromosome 16.

Q: Stevens-Johnson syndrome is most commonly associated with which of the following infectious agents?

Herpes simplex virus. **Explanation:** **Stevens-Johnson Syndrome (SJS)** and **Erythema Multiforme (EM)** are often discussed together as part of a spectrum of reactive dermatoses. While drugs (like sulfonamides, anticonvulsants, and NSAIDs) are the most common triggers for SJS/TEN, **infectious agents** play a significant role, particularly in recurrent cases. 1. **Why Herpes Simplex Virus (HSV) is correct:** HSV is the most frequently identified infectious trigger for the Erythema Multiforme/SJS spectrum. Specifically, HSV-1 and HSV-2 are associated with **Herpes-associated Erythema Multiforme (HAEM)**, which can progress to or present similarly to SJS in clinical scenarios. The viral DNA is often found in the keratinocytes, triggering a cell-mediated immune response that leads to epidermal necrosis. 2. **Why the other options are incorrect:** * **CMV and Varicella-zoster virus:** While these herpesviruses can occasionally trigger reactive skin rashes, they are significantly less common than HSV in the etiology of SJS. * **Toxoplasma gondii:** This is a protozoan parasite. While it can cause systemic illness, it is not a recognized primary trigger for SJS. **High-Yield Clinical Pearls for NEET-PG:** * **Most common overall cause of SJS:** Drugs (Sulfonamides are the #1 culprit). * **Most common infectious cause in children:** *Mycoplasma pneumoniae*. * **Most common viral cause:** Herpes Simplex Virus (HSV). * **Classification by Body Surface Area (BSA):** * SJS: 30%. * **Nikolsky Sign:** Characteristically positive in SJS/TEN due to the loss of cohesion in the epidermis.

Q: Sclerodema-like disorder is caused by which of the following?

All of the above. **Explanation:** **Scleroderma-like disorders** (also known as **Pseudo-scleroderma**) are a group of conditions that mimic the skin thickening and fibrosis seen in Systemic Sclerosis (SSc) but typically lack the characteristic internal organ involvement (like interstitial lung disease), Raynaud’s phenomenon, or specific autoantibodies (like anti-Scl-70). The correct answer is **All of the above** because each of these agents triggers distinct fibrotic pathways: 1. **Vinyl Chloride:** This is a classic occupational cause. Workers in the plastics industry exposed to vinyl chloride monomer can develop "Vinyl Chloride Disease," characterized by scleroderma-like skin changes, acro-osteolysis (resorption of distal phalanges), and Raynaud’s phenomenon. 2. **Bleomycin:** A chemotherapeutic agent known to induce skin fibrosis and pulmonary fibrosis. It increases the expression of Transforming Growth Factor-beta (TGF-β), the primary cytokine responsible for collagen synthesis. 3. **Pentazocine:** Chronic subcutaneous or intramuscular injections of this analgesic can lead to localized woody induration and fibrosis of the skin and underlying muscle at the injection sites. **High-Yield Clinical Pearls for NEET-PG:** * **Other Chemical Triggers:** Trichloroethylene, Epoxy resins, and L-tryptophan (Eosinophilia-Myalgia Syndrome). * **Drug-Induced:** Taxanes (Docetaxel) and Vitamin K1 injections can also cause similar changes. * **Distinguishing Feature:** Unlike systemic sclerosis, drug-induced scleroderma rarely involves the heart or kidneys and often improves upon withdrawal of the offending agent. * **Nephrogenic Systemic Fibrosis (NSF):** A scleroderma-mimic caused by **Gadolinium** contrast in patients with renal failure.

Q: Which of the following is a feature of Gorham syndrome?

Cutaneous hemangioma. **Explanation:** **Gorham Syndrome** (also known as Gorham-Stout disease or "Vanishing Bone Disease") is a rare musculoskeletal condition characterized by the proliferation of vascular or lymphatic channels, leading to the progressive destruction and resorption of bone (osteolysis). **Why Cutaneous Hemangioma is correct:** The hallmark of Gorham syndrome is the abnormal growth of blood vessels (angiomatosis) or lymphatic vessels. While the primary pathology occurs within the bone, approximately **10% of patients** present with associated **cutaneous hemangiomas** or vascular malformations overlying the affected skeletal site. These skin lesions serve as a vital clinical clue to the underlying vascular proliferation causing bone loss. **Analysis of Incorrect Options:** * **A. Hyperpigmentation:** This is not a characteristic feature of Gorham syndrome. Hyperpigmentation is more commonly associated with conditions like Addison’s disease or Melasma. * **C. Alloplasia:** This refers to the development of tissue at an abnormal site or into a different form. It is not a recognized feature of this angiomatous bone disorder. * **D. Photosensitivity:** This is a feature of connective tissue diseases (like SLE) or porphyrias, but it has no pathological link to the vascular/lymphatic proliferation seen in Gorham syndrome. **NEET-PG High-Yield Pearls:** * **Radiological Sign:** "Phantom bone" or "Vanishing bone" appearance due to cortical bone loss. * **Pathophysiology:** Replacement of normal bone with non-neoplastic vascular tissue. * **Key Association:** Chylothorax (if the ribs or thoracic vertebrae are involved), which significantly increases morbidity. * **Diagnosis:** Often a diagnosis of exclusion; biopsy shows thin-walled vascular channels replacing bone.

Question 1

Histological appearance of scleroderma includes all except?

Accepted Answer

Extensive fibrosis of upper 1/3 of the dermis

Answer

Decreased adnexal structures

Answer

Homogenization of collagen

Answer

Increased dermal thickness

Question 2

In which condition is mucocutaneous candidiasis an important clinical feature?

Accepted Answer

Autoimmune hypoparathyroidism

Answer

DiGeorge syndrome

Answer

Pseudohypoparathyroidism

Answer

Post-surgical hypoparathyroidism

Question 3

Which of the following is true about the chickenpox rash?

Accepted Answer

Pleomorphic

Answer

Polymorphic

Answer

Centripetal

Answer

Cytoplasmic inclusions

Question 4

Gottron papules are pathognomonic for which condition?

Accepted Answer

Dermatomyositis

Answer

Inclusion body myositis

Answer

Polymyositis

Answer

Discoid lupus erythematosus

Question 5

A 40-year-old woman presented with an 8-month history of erythema and swelling of the periorbital region, papules and plaques on the dorsolateral aspect of forearms and knuckles, and ragged cuticles. There was no muscle weakness. What is the most likely diagnosis?

Accepted Answer

Dermatomyositis

Answer

Systemic Lupus Erythematosus (SLE)

Answer

Systemic sclerosis

Answer

Mixed connective tissue disorder

Question 6

Which of the following statements is true regarding this skin disease?

Accepted Answer

All of the above.

Answer

Can cause premature coronary artery disease.

Answer

Can cause arthritis.

Answer

Itching can be present.

Question 7

What is the earliest presenting feature of tuberous sclerosis?

Accepted Answer

Ash leaf spot

Answer

Facial angiofibroma

Answer

Shagreen patch

Answer

Gingival fibroma

Question 8

Stevens-Johnson syndrome is most commonly associated with which of the following infectious agents?

Accepted Answer

Herpes simplex virus

Answer

Cytomegalovirus (CMV)

Answer

Varicella-zoster virus (Chickenpox)

Answer

Toxoplasma gondii

Question 9

Sclerodema-like disorder is caused by which of the following?

Accepted Answer

All of the above

Answer

Vinyl chloride

Answer

Bleomycin

Answer

Pentazocine

Question 10

Which of the following is a feature of Gorham syndrome?

Accepted Answer

Cutaneous hemangioma

Answer

Hyperpigmentation

Answer

Alloplasia

Answer

Photosensitivity

Autoimmune Skin Diseases — MCQs

Autoimmune Skin Diseases — MCQs

On this page

Practice by Chapter

Want unlimited practice?