Acne and Related Disorders — MCQs

Acne and Related Disorders Indian Medical PG Practice Questions and MCQs

Question 41: Acne vulgaris is caused by which of the following?

A. Staphylococcus aureus
B. Diphtheroids
C. Sweat gland hyperplasia
D. Obstruction to the pilosebaceous duct (Correct Answer)

Explanation: **Explanation:** Acne vulgaris is a chronic inflammatory disease of the **pilosebaceous unit**. The primary pathogenic event is **follicular hyperkeratinization**, which leads to the **obstruction of the pilosebaceous duct**. This obstruction creates a "keratin plug" (microcomedo), trapping sebum and providing an anaerobic, lipid-rich environment for the proliferation of *Cutibacterium acnes* (formerly *Propionibacterium acnes*). **Analysis of Options:** * **Option D (Correct):** Obstruction is the fundamental step in comedogenesis. The four key factors in acne pathogenesis are: 1) Follicular hyperkeratinization (obstruction), 2) Increased sebum production (androgen-mediated), 3) Colonization by *C. acnes*, and 4) Inflammation. * **Option A:** *Staphylococcus aureus* is a common cause of bacterial folliculitis or impetigo, but it is not the causative agent of acne. * **Option B:** While *C. acnes* is a diphtheroid (Gram-positive rod), the term "Diphtheroids" is too broad and non-specific. Furthermore, colonization is secondary to the initial ductal obstruction. * **Option C:** Acne involves **sebaceous gland** hyperactivity, not sweat gland hyperplasia. Sweat gland disorders include conditions like miliaria or hidradenitis suppurativa. **NEET-PG High-Yield Pearls:** * **Earliest Lesion:** The microcomedo is the first pathological change. * **Clinical Hallmark:** The presence of **comedones** (open/blackheads or closed/whiteheads) distinguishes acne from acneiform eruptions. * **Drug-Induced Acne:** Commonly caused by Steroids, Isoniazid (INH), Lithium, and Phenytoin. These typically present as monomorphic pustules without comedones. * **Treatment Gold Standard:** Topical retinoids are the first-line treatment for comedonal acne as they target the ductal obstruction.

Question 42: Collarette of scales is a characteristic feature of which of the following dermatological conditions?

A. Acne
B. Psoriasis
C. Pityriasis rosea (Correct Answer)
D. Pemphigus

Explanation: **Explanation:** **Pityriasis Rosea (PR)** is a self-limiting, inflammatory papulosquamous disorder. The characteristic **"Collarette of scales"** refers to a thin, peripheral ring of scaling where the scales are attached at the periphery and free towards the center. This is most classically seen in the **Herald Patch** (the initial, largest lesion) and subsequent smaller oval lesions that follow the lines of cleavage (Langer’s lines), creating a **"Christmas Tree" appearance** on the back. **Analysis of Options:** * **Acne (A):** Characterized by comedones, papules, pustules, and nodules. Scaling is not a primary feature unless caused by topical treatments (e.g., retinoids). * **Psoriasis (B):** Features **silvery-white, micaceous scales** that are thick and stratified. Key signs include the **Auspitz sign** (pinpoint bleeding on scale removal) and **Grattage test** positivity. * **Pemphigus (C):** An autoimmune blistering disease. It presents with fragile bullae that rupture to leave painful erosions and crusting, rather than a collarette of scales. **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Often associated with **HHV-6 and HHV-7** reactivation. * **Herald Patch:** The first lesion, usually 2–10 cm in diameter, appearing days to weeks before the generalized eruption. * **Differential Diagnosis:** Secondary syphilis (always rule this out if lesions involve palms and soles; PR typically spares them). * **Treatment:** Usually conservative (reassurance); acyclovir or UVB therapy may be used in severe cases.

Question 43: Tricholemmoma are:

A. Ectopic tuft of hair on face.
B. Teratoma of ovary containing mainly hair.
C. Adnexal tumors of skin that differentiate towards hair follicles. (Correct Answer)
D. Psychiatric illness in which patient picks on hair of skin.

Explanation: **Explanation:** **Tricholemmoma** is a benign cutaneous adnexal neoplasm that shows differentiation toward the **outer root sheath** of the hair follicle. The term is derived from "tricho" (hair) and "lemma" (sheath). Histologically, these tumors are characterized by well-circumscribed lobules of clear cells (due to glycogen content) surrounded by a palisaded layer of columnar cells and a thick basement membrane. **Analysis of Options:** * **Option C (Correct):** As stated, these are adnexal tumors specifically differentiating toward the hair follicle (specifically the outer root sheath). * **Option A (Incorrect):** An ectopic tuft of hair is a physical finding, not a specific neoplastic entity like tricholemmoma. * **Option B (Incorrect):** A teratoma of the ovary containing mainly hair and skin elements is known as a **Dermoid Cyst**. If it contains primarily thyroid tissue, it is called *Struma ovarii*. * **Option D (Incorrect):** The psychiatric impulse-control disorder where a patient pulls out their own hair is **Trichotillomania**. If they pick at their skin, it is known as *Dermatillomania* (Excoriation disorder). **High-Yield Clinical Pearls for NEET-PG:** * **Cowden Syndrome:** Multiple facial tricholemmomas are a pathognomonic marker for Cowden Syndrome (Multiple Hamartoma Syndrome), which is caused by a mutation in the **PTEN gene**. * **Associated Risks:** Patients with Cowden Syndrome have a significantly increased risk of **Breast cancer**, **Thyroid cancer** (follicular), and **Endometrial cancer**. * **Histology Keyword:** Look for "Clear cells" and "Peripheral palisading" on a biopsy report.

Question 44: A 28-year-old female presents with a rash. Which of the following conditions is NOT associated with an increased risk of developing this rash?

A. Internal malignancy
B. Polycystic Ovarian Disease (PCOD)
C. Diabetes mellitus
D. Niacin deficiency (Correct Answer)

Explanation: ***Niacin deficiency*** - **Niacin deficiency** causes **pellagra**, characterized by the "4 D's": dermatitis, diarrhea, dementia, and death - not acanthosis nigricans. - High-dose **niacin therapy** (not deficiency) can occasionally cause acanthosis nigricans as a side effect. *Internal malignancy* - **Gastric adenocarcinoma** is the most common malignancy associated with **paraneoplastic acanthosis nigricans**. - The rash may appear suddenly and be more extensive, often involving **mucosal surfaces** like the oral cavity. *Polycystic Ovarian Disease (PCOD)* - **Insulin resistance** in PCOD leads to hyperinsulinemia, which stimulates **insulin-like growth factor-1 (IGF-1) receptors**. - This causes **keratinocyte proliferation** and the characteristic velvety, hyperpigmented plaques of acanthosis nigricans. *Diabetes mellitus* - **Type 2 diabetes** with insulin resistance commonly presents with acanthosis nigricans, especially in **skin folds**. - The condition often improves with **glycemic control** and weight reduction, indicating its metabolic association.

Question 45: Recalcitrant pustular acne is treated by which of the following?

A. Oral Erythromycin
B. Oral tetracycline
C. Steroids
D. Retinoids (Correct Answer)

Explanation: **Explanation:** **Why Retinoids are the correct answer:** Oral **Isotretinoin** (a 1st-generation systemic retinoid) is the gold standard for severe, nodulocystic, or **recalcitrant** (treatment-resistant) acne. It is the only drug that targets all four pathogenic mechanisms of acne: 1. Reduction of sebum production (shrinks sebaceous glands). 2. Normalization of follicular keratinization (prevents comedone formation). 3. Inhibition of *Cutibacterium acnes* proliferation (by altering the microenvironment). 4. Anti-inflammatory properties. For pustular acne that has failed to respond to standard antibiotic therapy, retinoids are the definitive next step in management. **Analysis of Incorrect Options:** * **A & B (Oral Erythromycin/Tetracycline):** These are first-line systemic antibiotics for moderate inflammatory acne. However, "recalcitrant" by definition means the acne has failed to respond to these conventional treatments or has relapsed quickly after stopping them. * **C (Steroids):** While systemic steroids (like Prednisolone) are used in specific emergencies like **Acne Fulminans** or to prevent "flares" when starting isotretinoin, they are not a primary treatment for recalcitrant pustular acne and can actually cause "steroid acne" if used inappropriately. **High-Yield Clinical Pearls for NEET-PG:** * **Most common side effect of Isotretinoin:** Cheilitis (dryness of lips). * **Most serious side effect:** Teratogenicity (requires two forms of contraception; the "iPLEDGE" program). * **Monitoring:** Baseline and periodic Lipid Profile and Liver Function Tests (LFTs) are mandatory. * **Drug Interaction:** Never co-administer Isotretinoin with Tetracyclines due to the increased risk of **Pseudotumor Cerebri** (Benign Intracranial Hypertension).

Question 46: All of the following are variants of Acne, EXCEPT:

A. Acne conglobata
B. Acne agminata (Correct Answer)
C. Acne fulminans
D. Pomade acne

Explanation: **Explanation:** The correct answer is **Acne agminata**. Despite its name, Acne agminata is **not** a variant of acne vulgaris. It is a chronic granulomatous inflammatory condition, currently considered a variant of **Lupus Miliaris Disseminatus Faciei (LMDF)**. It is characterized by small, reddish-brown papules on the face (especially the eyelids) that histologically show "naked" caseating granulomas. It is not related to the pilosebaceous unit pathology seen in acne. **Analysis of Incorrect Options:** * **Acne conglobata:** A severe, chronic form of inflammatory acne characterized by interconnecting abscesses, cysts, and sinus tracts. It is part of the "Follicular Occlusion Tetrad." * **Acne fulminans:** The most severe form of acne, presenting with sudden onset of painful, ulcerated, hemorrhagic crusting. It is unique because it is associated with **systemic symptoms** (fever, polyarthritis, and leukocytosis) and often requires systemic steroids along with Isotretinoin. * **Pomade acne:** A form of *Acne venenata* (contact acne) caused by the application of greasy or oily grooming products to the scalp and forehead, leading to comedone formation. **High-Yield Clinical Pearls for NEET-PG:** * **Follicular Occlusion Tetrad:** Includes Acne conglobata, Hidradenitis suppurativa, Dissecting cellulitis of the scalp, and Pilonidal sinus. * **SAPHO Syndrome:** Synovitis, Acne (conglobata/fulminans), Pustulosis, Hyperostosis, and Osteitis. * **Drug-induced Acne:** Commonly caused by Steroids (monomorphic papules without comedones), Isoniazid (INH), Lithium, and Phenytoin. * **Acne Fulminans Trigger:** Can be paradoxically triggered by starting high-dose Isotretinoin; hence, low-dose initiation is recommended in severe cases.

Question 47: Which of the following is NOT a component of SAPHO syndrome?

A. Acne
B. Hyperostosis
C. Osteitis
D. Acantholysis (Correct Answer)

Explanation: **Explanation:** **SAPHO syndrome** is a rare, chronic inflammatory disorder characterized by a constellation of cutaneous and musculoskeletal manifestations. The name is an acronym where each letter represents a core component of the syndrome: * **S:** **S**ynovitis (inflammation of the joints) * **A:** **A**cne (specifically severe forms like Acne conglobata or Acne fulminans) * **P:** **P**ustulosis (often Palmoplantar pustulosis) * **H:** **H**yperostosis (excessive bone growth, typically involving the sternoclavicular region) * **O:** **O**steitis (inflammation of the bone) **Why Option D is correct:** **Acantholysis** refers to the loss of intercellular connections (desmosomes) between keratinocytes, leading to the formation of intraepidermal vesicles or bullae. This is the hallmark histological feature of **Pemphigus** group of diseases, not SAPHO syndrome. **Why other options are incorrect:** * **Option A (Acne):** Severe inflammatory acne is a diagnostic criterion for the syndrome. * **Option B & C (Hyperostosis & Osteitis):** These represent the hallmark musculoskeletal involvement. The anterior chest wall (sternoclavicular joint) is the most common site of involvement in adults, showing characteristic "bull's head" appearance on bone scintigraphy. **High-Yield Clinical Pearls for NEET-PG:** * **Treatment of Choice:** NSAIDs are first-line for pain; **Bisphosphonates** (like Pamidronate) are highly effective for bone pain and osteitis. * **Radiology:** Look for the **"Bull’s Head Sign"** on Technetium-99m bone scan, representing increased uptake in the sternocostoclavicular region. * **Associated Acne:** Often associated with **Acne Fulminans**, which can also present with systemic symptoms like fever and polyarthritis.

Question 48: Which of the following is NOT a causative factor for acne vulgaris?

A. Androgen stimulation
B. Dietary factors alone (Correct Answer)
C. Bacterial contamination
D. Hypercornification of the duct

Explanation: **Explanation:** Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit. Its pathogenesis is multifactorial, involving four primary interrelated mechanisms. **Why "Dietary factors alone" is the correct answer:** While diet (specifically high glycemic index foods and dairy) is considered a *modulating* or *exacerbating* factor in some patients, it is not a primary causative mechanism. Current dermatological consensus states that diet alone cannot cause acne in the absence of the underlying pathophysiological processes. **Analysis of Incorrect Options (Primary Pathogenic Factors):** * **Androgen stimulation (A):** Androgens (specifically DHT) stimulate sebaceous glands to increase sebum production. This is the prerequisite for acne development. * **Bacterial contamination (C):** Specifically, the proliferation of *Cutibacterium acnes* (formerly *Propionibacterium acnes*) within the sebum-rich follicle triggers inflammatory pathways. * **Hypercornification of the duct (D):** Abnormal follicular keratinization leads to the formation of a "keratin plug," obstructing the pilosebaceous duct and forming the microcomedo (the precursor to all acne lesions). **High-Yield Clinical Pearls for NEET-PG:** * **The "Tetrad" of Acne Pathogenesis:** 1. Hyperkeratosis (Ductal obstruction), 2. Sebum overproduction, 3. *C. acnes* colonization, 4. Inflammation. * **First visible lesion:** Microcomedo. * **First clinically visible lesion:** Open/Closed Comedones. * **Drug-induced acne:** Steroids, Isoniazid (INH), Lithium, and Phenytoin are common culprits. Note that drug-induced acne is typically **monomorphic** (all lesions at the same stage) and lacks comedones. * **Severe Variant:** Acne Fulminans (associated with systemic symptoms like fever and joint pain; treated with systemic steroids + Isotretinoin).

Question 49: When a patient is on isotretinoin therapy, which of the following parameters should be monitored?

A. Liver function tests
B. Lipid profile (Correct Answer)
C. Renal function tests
D. Complete blood count (CBC)

Explanation: **Explanation:** Isotretinoin (13-cis-retinoic acid) is a potent systemic retinoid used for severe, recalcitrant acne. Monitoring is crucial due to its systemic metabolic effects. **Why Lipid Profile is the Correct Answer:** Isotretinoin significantly alters lipid metabolism. It commonly causes **hypertriglyceridemia** (seen in ~25% of patients) and, to a lesser extent, increases in total cholesterol and LDL, while decreasing HDL. Severe hypertriglyceridemia (>800 mg/dL) poses a high risk for **acute pancreatitis**, making regular lipid profile monitoring the standard of care during therapy. **Analysis of Incorrect Options:** * **A. Liver Function Tests (LFTs):** While isotretinoin can cause a transient rise in transaminases, modern guidelines emphasize that significant hepatotoxicity is rare. While LFTs are often checked at baseline, **Lipid Profile** is prioritized in many exam contexts because the metabolic shift is more frequent and carries the acute risk of pancreatitis. (Note: In clinical practice, both are often monitored, but lipids are the classic "high-yield" metabolic concern). * **C. Renal Function Tests:** Isotretinoin is primarily metabolized by the liver and excreted via feces and urine; it is not nephrotoxic. * **D. Complete Blood Count (CBC):** Systemic retinoids do not typically cause bone marrow suppression or significant hematological changes. **Clinical Pearls for NEET-PG:** * **Teratogenicity:** The most serious side effect. Pregnancy must be excluded (2 negative tests) before starting, and two forms of contraception are required (**iPLEDGE program**). * **Mucocutaneous effects:** Cheilitis (most common side effect), xerosis, and epistaxis. * **Ocular:** Decreased night vision and dry eyes. * **Musculoskeletal:** Myalgia and premature epiphyseal closure (in children). * **Psychiatric:** Possible association with depression and suicidal ideation.

Question 50: In sebaceous glands, what does the accumulation of sebum lead to?

A. Milia
B. Acne (Correct Answer)
C. Epidermoid cyst
D. Miliaria

Explanation: **Explanation:** The correct answer is **Acne (Acne Vulgaris)**. The pathogenesis of acne is multifactorial, but the primary initiating event is the formation of a **microcomedo**. This occurs due to follicular hyperkeratinization and increased sebum production (stimulated by androgens). When sebum accumulates within the pilosebaceous unit, it creates an obstructive plug. This stagnant sebum serves as a nutrient source for *Cutibacterium acnes*, leading to inflammation and the clinical presentation of comedones, papules, and pustules. **Analysis of Incorrect Options:** * **Milia:** These are small, superficial keratin-filled cysts (not sebum) derived from the pilosebaceous unit or eccrine sweat ducts. They appear as pearly white papules, commonly on the face. * **Epidermoid Cyst:** While these involve the follicular infundibulum, they are caused by the proliferation of epidermal cells within a circumscribed dermal space, leading to a cyst filled with **keratin**, not just sebum accumulation. * **Miliaria:** This condition (prickly heat) is caused by the blockage of **eccrine sweat glands**, leading to the retention of sweat, not sebum. **High-Yield Clinical Pearls for NEET-PG:** * **Four Key Factors in Acne:** 1. Hyperkeratinization, 2. Sebum overproduction, 3. *C. acnes* colonization, 4. Inflammation. * **Drug-Induced Acne:** Commonly caused by Steroids, Isoniazid (INH), Lithium, and Phenytoin. (Mnemonic: **SILP**) * **First-line treatment:** Topical retinoids (comedolytic) are the mainstay for mild acne; Oral Isotretinoin is the drug of choice for severe nodulocystic acne.

Practice by Chapter

Acne Vulgaris: Pathophysiology

Practice Questions

Acne Vulgaris: Clinical Types

Practice Questions

Acne Vulgaris: Management

Practice Questions

Acne in Special Populations

Practice Questions

Rosacea

Practice Questions

Perioral Dermatitis

Practice Questions

Hidradenitis Suppurativa

Practice Questions

Acne Keloidalis Nuchae

Practice Questions

Acne Scarring and Its Management

Practice Questions

Psychological Aspects of Acne

Practice Questions

Diet and Acne

Practice Questions

Newer Therapies in Acne Management

Practice Questions

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