Dermatology
7 questionsTreatment of dermatitis herpetiformis:
What is the most common trigger associated with erythema multiforme?
Acantholysis is not seen in:
Nikolsky's sign is associated with which of the following conditions?
What is the treatment of choice for lichen planus?
The Grattage test is used to diagnose which of the following conditions?
Most common metal in contact allergic dermatitis is?
NEET-PG 2013 - Dermatology NEET-PG Practice Questions and MCQs
Question 1131: Treatment of dermatitis herpetiformis:
- A. Dapsone
- B. Sulfonamide
- C. Gluten-free diet
- D. All of the options (Correct Answer)
Explanation: ***All of the options*** - **Dermatitis herpetiformis (DH)** is a chronic, intensely itchy blistering skin condition associated with **celiac disease**. - Effective management involves both a **gluten-free diet** to address the underlying autoimmune process and medications like **dapsone** or **sulfonamides** for symptomatic relief. *Gluten-free diet* - A strict **gluten-free diet** is crucial for long-term management as it addresses the underlying small intestinal enteropathy associated with **celiac disease** and **dermatitis herpetiformis**. - While it may take several months to see full skin improvement, it can eventually lead to resolution of skin lesions and reduced or eliminated need for medication. *Dapsone* - **Dapsone** is a rapidly effective medication for alleviating the intense itching and rash of **dermatitis herpetiformis**, often providing relief within 24-48 hours. - It works by inhibiting neutrophil migration and inflammation, but does not treat the underlying gluten-sensitive enteropathy. *Sulfonamide* - **Sulfonamides**, such as sulfapyridine or sulfamethoxypyridazine, can be used as an alternative for patients who cannot tolerate **dapsone** or who respond inadequately to it. - Like dapsone, these medications provide symptomatic relief by reducing inflammation and neutrophil activity in the skin, but do not address the gluten-induced intestinal damage.
Question 1132: What is the most common trigger associated with erythema multiforme?
- A. Herpes simplex (Correct Answer)
- B. Mycoplasma pneumoniae
- C. TB
- D. Drugs
Explanation: ***Herpes simplex*** - **Herpes simplex virus (HSV)** is the most common precipitating factor for **erythema multiforme**, accounting for **50-60% of identifiable cases**, particularly the recurrent form. - The rash typically appears **10-14 days after an HSV outbreak**, suggesting an immune-mediated reaction. - **HSV-1** is more commonly implicated than HSV-2. *Mycoplasma pneumoniae* - **Mycoplasma pneumoniae** is the **second most common infectious trigger** for erythema multiforme, especially in children and young adults. - EM associated with Mycoplasma typically occurs during or after respiratory infection. - However, it is still less common than HSV as a trigger. *TB* - **Tuberculosis (TB)** is not typically associated with erythema multiforme. - While other infections can trigger erythema multiforme, TB is rarely implicated. *Drugs* - **Drug reactions** are a recognized cause of erythema multiforme, but they are less common than HSV infection as a trigger. - Certain medications like **sulfonamides, anticonvulsants, NSAIDs, and penicillins** are among the drugs that can induce erythema multiforme.
Question 1133: Acantholysis is not seen in:
- A. Lichen planus (Correct Answer)
- B. Dermatitis herpetiformis
- C. Hailey-Hailey disease
- D. Bullous pemphigoid
Explanation: ***Lichen planus*** - **Lichen planus** is a **non-blistering inflammatory dermatosis** where **acantholysis is completely absent** as it is not a blistering disorder. - Characterized by **acanthosis** (epidermal thickening), **hyperkeratosis**, **wedge-shaped hypergranulosis**, and a **band-like lymphocytic infiltrate** at the dermo-epidermal junction. - The pathology involves **basal cell liquefaction** and inflammation, not loss of keratinocyte cohesion. - **Most appropriate answer** as lichen planus is fundamentally a non-blistering condition, unlike the other options which are blistering diseases. *Bullous pemphigoid* - A **subepidermal bullous disease** where blister formation occurs *below* the epidermis at the **dermo-epidermal junction**. - Autoantibodies target **BP180 and BP230** antigens in **hemidesmosomes**, causing separation between epidermis and dermis. - **No acantholysis** is present as keratinocytes within the epidermis remain cohesive; the split is subepidermal. - Also a correct answer, but less optimal than lichen planus as it is still a blistering disease. *Dermatitis herpetiformis* - A **subepidermal blistering disease** associated with **celiac disease** and characterized by intensely pruritic papulovesicles. - Features **neutrophilic microabscesses** in dermal papillae and granular **IgA deposits** at the dermo-epidermal junction. - **No acantholysis** as blister formation is subepidermal due to immune complex deposition, not loss of keratinocyte adhesion. - Also technically correct, but lichen planus remains the best answer. *Hailey-Hailey disease* - **INCORRECT:** This condition is characterized by **suprabasal acantholysis**, making it a classic example where acantholysis IS present. - Also known as **familial benign chronic pemphigus**, caused by mutation in **ATP2C1 gene** affecting calcium regulation. - Leads to chronic, relapsing blistering and erosions in **intertriginous areas** (axillae, groin). - **Acantholysis is the defining histological feature**, producing a "dilapidated brick wall" appearance.
Question 1134: Nikolsky's sign is associated with which of the following conditions?
- A. Herpes zoster
- B. Bullous impetigo
- C. All of the options
- D. Pemphigus (Correct Answer)
Explanation: ***Pemphigus*** - **Nikolsky's sign** is the **most characteristic and consistent** clinical finding in pemphigus, where slight lateral pressure on seemingly normal skin near a blister or erosion causes the epidermis to shear off, forming a new blister or denudation. - This sign indicates **intraepidermal blistering** due to the loss of cell adhesion (acantholysis) caused by autoantibodies against desmoglein proteins. - **Pemphigus is the classic condition** associated with a positive Nikolsky's sign in medical literature and examinations. *Herpes zoster* - **Herpes zoster** (shingles) is characterized by painful, vesicular eruptions in a **dermatomal distribution**, which do **not exhibit Nikolsky's sign**. - The vesicles in herpes zoster are **intraepidermal** but result from viral cytopathic effect, not acantholysis, and the roof of the vesicle remains intact with lateral pressure. *Bullous impetigo* - Bullous impetigo is a superficial skin infection caused by *Staphylococcus aureus* that produces **large, flaccid blisters**. - While **Nikolsky's sign can occasionally be positive** in bullous impetigo (particularly in staphylococcal scalded skin syndrome), it is **much less consistent and prominent** compared to pemphigus. - The key distinction is that pemphigus remains the **most characteristic association** with Nikolsky's sign in clinical practice and examinations. *All of the options* - This option is incorrect because Nikolsky's sign is **most specifically and consistently associated with pemphigus**. - While bullous impetigo may occasionally show Nikolsky's sign, **pemphigus is the classic answer** for this clinical finding in medical examinations.
Question 1135: What is the treatment of choice for lichen planus?
- A. Topical corticosteroids (Correct Answer)
- B. Systemic corticosteroids
- C. Antihistamines
- D. Acitretin
Explanation: ***Topical corticosteroids*** - **Topical corticosteroids** are the first-line treatment for localized lichen planus due to their potent **anti-inflammatory** and **immunosuppressive** effects. - They effectively reduce **itching**, **inflammation**, and the characteristic **violaceous papules** of lichen planus. *Systemic corticosteroids* - **Systemic corticosteroids** are typically reserved for widespread, severe, or refractory cases of lichen planus, not as initial treatment. - Their use is limited by potential **systemic side effects**, such as **osteoporosis**, **hypertension**, and **diabetes**. *Antihistamines* - **Antihistamines** primarily target **itching** (pruritus) associated with lichen planus but do not address the underlying **inflammatory process** or resolve the skin lesions themselves. - They may be used as an adjunct for symptomatic relief, especially for nocturnal pruritus. *Acitretin* - **Acitretin** is a **retinoid** used for severe or refractory cases of lichen planus (including erosive, oral, and hypertrophic variants), but not as first-line treatment for localized cutaneous disease. - It carries significant **teratogenic risks** and other side effects, making it unsuitable as initial therapy when topical corticosteroids are effective.
Question 1136: The Grattage test is used to diagnose which of the following conditions?
- A. Tinea capitis
- B. Lichen planus
- C. Pemphigus vulgaris
- D. Psoriasis (Correct Answer)
Explanation: ***Psoriasis*** - The **Grattage test** (candle grease sign) involves **scraping the psoriatic lesion** to reveal characteristic features - First reveals **fine, silvery-white scales** resembling candle wax - Further scraping exposes **pinpoint bleeding points** (**Auspitz sign**) due to exposure of dilated capillaries in dermal papillae - This combination is **pathognomonic for psoriasis** and helps differentiate it from other scaly dermatoses *Tinea capitis* - A **fungal infection of the scalp** caused by dermatophytes - Diagnosed by **KOH mount** (showing fungal hyphae), **fungal culture**, and sometimes **Wood's lamp examination** - The Grattage test is not used for diagnosing fungal infections *Lichen planus* - Characterized by **purplish, polygonal, flat-topped, pruritic papules and plaques** - Surface shows **Wickham's striae** (fine white lines) - Diagnosis is **clinical**, supported by **skin biopsy** showing band-like lymphocytic infiltrate and sawtooth rete ridges - The Grattage test is not applicable *Pemphigus vulgaris* - A severe **autoimmune blistering disorder** with **suprabasal acantholysis** - Presents with **flaccid bullae** that rupture easily, leaving erosions - Diagnosed by **skin biopsy**, **direct immunofluorescence** (intercellular IgG and C3 deposits), and **Nikolsky's sign** (positive) - The Grattage test is not used for bullous disorders
Question 1137: Most common metal in contact allergic dermatitis is?
- A. Gold
- B. Silver
- C. Aluminum
- D. Nickel (Correct Answer)
Explanation: ***Nickel*** - **Nickel** is the most frequent cause of **metal-induced contact allergic dermatitis**, affecting a significant portion of the population. - It is commonly found in jewelry, belt buckles, buttons, and other everyday metallic objects. *Gold* - **Gold allergy** can occur but is much less common than nickel allergy. - Reactions typically arise from jewelry and may involve **allergic contact dermatitis**. *Silver* - **Silver allergy** is quite rare and often due to impurities or alloys rather than pure silver itself. - Pure silver is generally considered **hypoallergenic**. *Aluminum* - **Aluminum** is generally not a common cause of **allergic contact dermatitis**. - While it can be an irritant in some products (e.g., antiperspirants), true allergic reactions are infrequent.
Obstetrics and Gynecology
1 questionsWhich type of suture is primarily used for the repair of a complete perineal tear?
NEET-PG 2013 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 1131: Which type of suture is primarily used for the repair of a complete perineal tear?
- A. Monocryl
- B. Catgut
- C. Silk
- D. Vicryl (Correct Answer)
Explanation: ***Correct Answer: Vicryl (Polyglactin 910)*** - **Vicryl is the gold standard suture material** for repair of complete perineal tears (third and fourth-degree) - It is a **synthetic absorbable braided suture** with excellent tensile strength that maintains tissue support during critical healing phase - **Absorption profile**: Loses 50% tensile strength by 2 weeks, completely absorbed in 56-70 days, ideal for perineal tissue healing - **Minimal tissue reaction** and low infection risk compared to natural sutures - **Recommended by RCOG and ACOG guidelines** for layer-by-layer repair of perineal tears involving anal sphincter *Incorrect: Monocryl* - Monocryl (Poliglecaprone 25) is a fast-absorbing monofilament suture primarily used for **subcuticular skin closure** - Not the first choice for deep tissue repair of complete perineal tears - Has faster absorption (90-120 days) which may not provide adequate support for sphincter repair *Incorrect: Catgut* - Catgut is a natural absorbable suture that was **historically used but is now largely obsolete** - **Higher tissue reaction**, increased infection risk, and unpredictable absorption make it unsuitable - Modern synthetic sutures like Vicryl have replaced catgut in current obstetric practice *Incorrect: Silk* - Silk is a **non-absorbable suture** that is inappropriate for perineal repair - Would require removal and carries risk of chronic foreign body reaction - Never used for internal structures in perineal reconstruction
Pathology
1 questionsWhat does a Tzanck smear in varicella-zoster virus infection typically show?
NEET-PG 2013 - Pathology NEET-PG Practice Questions and MCQs
Question 1131: What does a Tzanck smear in varicella-zoster virus infection typically show?
- A. Acantholytic cells
- B. Epidermal spongiosis
- C. Multinucleated giant cells (Correct Answer)
- D. Necrotic cells
Explanation: ***Multinucleated giant cells*** - A Tzanck smear identifies **multinucleated giant cells** with intranuclear inclusions, which are characteristic **cytopathic effects** of herpesviruses like VZV [1]. - These cells result from the fusion of infected keratinocytes, a hallmark finding in **herpes simplex** and **varicella-zoster infections** [1]. *Acantholytic cells* - Acantholytic cells are seen in conditions like **pemphigus vulgaris**, where there is loss of cell-to-cell adhesion between keratinocytes, leading to intraepidermal blistering. - While VZV can cause blistering, the primary cytological finding on Tzanck smear is not acantholysis but rather the presence of multinucleated cells. *Epidermal spongiosis* - Spongiosis refers to **intercellular edema** of epidermal cells, leading to widening of the intercellular spaces, typically seen in **eczematous dermatoses** [1]. - This finding is not specific to viral infections and does not represent the characteristic cytopathic effect of VZV on a Tzanck smear. *Necrotic cells* - Necrotic cells, or dead cells, are a general finding in many inflammatory and infectious processes where tissue damage occurs. - While VZV infection can lead to cell necrosis, the presence of isolated necrotic cells is not the specific, diagnostic feature for VZV on a Tzanck smear. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 366-367.
Pharmacology
1 questionsWhich drug would be most appropriate for treating a patient with suspected chlamydia-gonorrhea coinfection?
NEET-PG 2013 - Pharmacology NEET-PG Practice Questions and MCQs
Question 1131: Which drug would be most appropriate for treating a patient with suspected chlamydia-gonorrhea coinfection?
- A. Ciprofloxacin
- B. Nalidixic acid
- C. Doxycycline (Correct Answer)
- D. Norfloxacin
Explanation: ***Doxycycline*** - **Doxycycline** is a highly effective treatment for **chlamydia**, and its broad-spectrum activity also covers potential **gonorrhea coinfection** when used as part of a dual therapy regimen. - It is often prescribed alongside a **single dose of ceftriaxone** for presumed gonorrhea coinfection, as ceftriaxone targets gonorrhea while doxycycline targets chlamydia. *Ciprofloxacin* - **Ciprofloxacin** is a **fluoroquinolone** antibiotic, which is generally not recommended as first-line treatment for uncomplicated **gonorrhea** or **chlamydia** due to increasing resistance. - It has activity against *Neisseria gonorrhoeae*, but its effectiveness against *Chlamydia trachomatis* is suboptimal compared to macrolides or tetracyclines. *Norfloxacin* - **Norfloxacin** is another **fluoroquinolone** with a narrower spectrum of activity than ciprofloxacin and is primarily used for **urinary tract infections**. - It has **poor efficacy against chlamydia** and is not a recommended treatment for either organism in this context. *Nalidixic acid* - **Nalidixic acid** is a first-generation **quinolone** with a very limited spectrum, used mainly for **gram-negative urinary tract infections**. - It has **no significant activity against chlamydia** or gonorrhea and is therefore inappropriate for treating this suspected coinfection.