Dermatology
2 questionsWhich of the following skin lesions is not classified as a nevus of melanocytes?
Which of the following is NOT a feature of atopic dermatitis?
NEET-PG 2012 - Dermatology NEET-PG Practice Questions and MCQs
Question 791: Which of the following skin lesions is not classified as a nevus of melanocytes?
- A. Dysplastic nevus
- B. Congenital melanocytic nevus
- C. Mongolian spot
- D. Becker nevus (Correct Answer)
Explanation: ***Becker nevus*** - A **Becker nevus** is a **hamartoma** of the **epidermis, dermis, and hair follicles**, characterized by increased epidermal basal layer pigmentation and smooth muscle hyperplasia. - While it contains increased **melanin**, it does **not** involve a proliferation of **melanocytes** themselves, differentiating it from true melanocytic nevi. - It is an **organoid hamartoma** with epidermal and dermal components, not a melanocytic lesion. *Mongolian spot* - A **Mongolian spot** is a **dermal melanocytosis** where melanocytes are entrapped in the dermis during their migration from the neural crest to the epidermis. - While technically termed a "melanocytosis" rather than a "nevus," it represents an **ectopic collection of dermal melanocytes** and is classified among melanocytic lesions. - Unlike Becker nevus, it involves an actual abnormal distribution of melanocytes (not just increased melanin). *Congenital melanocytic nevus* - A **congenital melanocytic nevus** is a benign proliferation of **melanocytes** present at birth, involving the dermis and/or epidermis. - These are true **melanocytic nevi**, with a risk of malignant transformation, particularly in larger lesions (>20 cm). *Dysplastic nevus* - A **dysplastic nevus** (atypical nevus) is an atypical melanocytic nevus with architectural and cytological atypia, considered a potential precursor to melanoma. - It is classified as a **melanocytic nevus** due to the proliferation of atypical melanocytes with architectural disorder.
Question 792: Which of the following is NOT a feature of atopic dermatitis?
- A. Dennie-Morgan fold
- B. Darier’s Sign (Correct Answer)
- C. Hyperlinearity of palms
- D. Hertoghe’s sign
Explanation: ***Darier's Sign*** - **Darier's sign** is characteristic of **urticaria pigmentosa** (cutaneous mastocytosis), where rubbing a skin lesion causes the formation of an urticarial wheal due to mast cell degranulation - It is **not associated** with the pathogenesis or clinical presentation of **atopic dermatitis** *Dennie-Morgan fold* - **Dennie-Morgan folds** are extra folds or lines in the skin just below the lower eyelids - They are a common clinical sign observed in patients with **atopic dermatitis**, often linked to chronic inflammation and allergic reactions affecting the skin around the eyes *Hertoghe's sign* - **Hertoghe's sign** refers to the thinning or absence of the lateral third of the eyebrows - This sign is often seen in individuals with **atopic dermatitis**, as well as in other conditions like hypothyroidism *Hyperlinearity of palms* - **Hyperlinearity of palms** refers to the exaggerated creases and lines on the palms of the hands - This is a common **stigmata of atopy** and is frequently observed in patients with **atopic dermatitis**, reflecting the underlying predisposition to skin dryness and altered epidermal barrier function
Obstetrics and Gynecology
5 questionsWhich of the following statements about Asherman's syndrome is true?
Which fetal presentation is the rarest?
Vaginal pH before puberty is?
What is the typical pH of the vagina in a pregnant woman?
Which IUD is preferred for menorrhagia?
NEET-PG 2012 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 791: Which of the following statements about Asherman's syndrome is true?
- A. May be secondary to TB
- B. Progesterone challenge test is positive
- C. Characterized by intrauterine adhesions (Correct Answer)
- D. Not associated with menstrual irregularities
Explanation: ***Characterized by intrauterine adhesions*** - **Asherman's syndrome** is fundamentally defined by the presence of **intrauterine adhesions** or scarring of the uterine cavity. - These adhesions develop following trauma to the basal layer of the endometrium, often from gynecological procedures like **dilation and curettage (D&C)**. - This is the **pathognomonic feature** that defines the syndrome. *Progesterone challenge test is positive* - The **progesterone challenge test** assesses the presence of an intact endometrium and adequate estrogen priming. - In Asherman's syndrome, due to the scarred endometrium, the response to progesterone is typically **absent or minimal**, leading to a **negative** result. - A negative progesterone challenge test indicates outflow obstruction or endometrial non-responsiveness. *May be secondary to TB* - While **genital tuberculosis** can cause intrauterine adhesions and is a recognized etiology, it represents a **small minority** of cases. - The primary etiology of Asherman's syndrome is usually **iatrogenic**, following uterine instrumentation such as D&C, particularly post-partum or post-abortion. - TB-related adhesions may have additional features like caseating granulomas. *Not associated with menstrual irregularities* - This is **false** - Asherman's syndrome is classically associated with **menstrual irregularities**. - Common presentations include **hypomenorrhea** (scanty periods), **amenorrhea** (absent periods), or oligomenorrhea. - These menstrual changes result from the reduced functional endometrium available for cyclical shedding due to intrauterine adhesions.
Question 792: Which fetal presentation is the rarest?
- A. Cephalic
- B. Breech
- C. Shoulder (Correct Answer)
- D. Face
Explanation: ***Shoulder*** - **Shoulder presentation** (also known as a **transverse lie**) occurs in approximately **0.3% of pregnancies** at term, making it the rarest presentation among the major fetal lie categories. - In this presentation, the fetal long axis is perpendicular to the maternal long axis, and the **shoulder** is typically the presenting part. - Vaginal delivery is not possible, and **cesarean section is mandatory**. *Cephalic* - **Cephalic presentation** is the most common presentation, occurring in about **95% of pregnancies**. - In this presentation, the fetal head is directed downwards towards the maternal pelvis. - This includes vertex, face, brow, and other head-first presentations. *Breech* - **Breech presentation** occurs when the fetal buttocks or feet are the presenting part, seen in about **3-4% of term pregnancies**. - While less common than cephalic, it is significantly more frequent than shoulder presentation. - Includes frank, complete, and footling breech variants. *Face* - **Face presentation** is a rare variant of cephalic presentation where the **fetal face** (chin/mentum) is the presenting part, occurring in about **0.2-0.3% of deliveries**. - The fetal head is hyperextended, with the occiput against the fetal back. - While rare, it is still slightly more common than shoulder presentation in some studies.
Question 793: Vaginal pH before puberty is?
- A. Approximately 6
- B. Approximately 4.5
- C. Approximately 5
- D. Neutral (around 7) (Correct Answer)
Explanation: ***Neutral (around 7)*** - Before puberty, the vagina lacks the influence of **estrogen**, which is essential for the colonization of **Lactobacillus** bacteria. - Without Lactobacillus, there is no significant production of lactic acid, resulting in a **neutral pH** environment. *Approximately 6* - A pH of approximately 6 is still slightly acidic but less so than a mature vagina. - This value is not typical for the prepubertal stage, which generally represents an environment without significant acidic production. *Approximately 4.5* - A pH of approximately 4.5 is characteristic of a **healthy, estrogenized adult vagina** where **Lactobacillus** bacteria produce lactic acid. - This acidic environment is crucial for protecting against pathogenic infections and is not found in prepubertal individuals. *Approximately 5* - A pH of approximately 5 is acidic, though less so than the optimal adult vaginal pH. - This value indicates some lactic acid production, which is minimal or absent before the onset of puberty.
Question 794: What is the typical pH of the vagina in a pregnant woman?
- A. 4.0 (Correct Answer)
- B. 4.5
- C. 5
- D. >5
Explanation: ***4.0*** - The typical vaginal pH in a pregnant woman is **acidic**, generally ranging from 3.5 to 4.5, with **4.0 being the most commonly cited average value** during pregnancy. - This **acidic environment** is crucial for maintaining a healthy vaginal flora, primarily dominated by **Lactobacillus species**, which produce lactic acid from glycogen deposits in vaginal epithelium. - The increased estrogen levels during pregnancy promote glycogen deposition, supporting lactobacilli growth and maintaining this acidic pH. *4.5* - While 4.5 is **also within the normal range** (3.5-4.5) for pregnant women, it represents the **upper limit** of normal vaginal pH during pregnancy. - Although still physiologic, **4.0 is more commonly referenced** as the typical value in obstetric literature, making it the best answer for "typical" pH. - A pH consistently at 4.5 or trending upward may warrant monitoring, though it is not necessarily pathological. *5* - A pH of 5 is considered **elevated** and is typically associated with conditions like **bacterial vaginosis** (BV) or **trichomoniasis**, which increase the risk of preterm labor and other complications. - A pH of 5 in pregnancy would raise suspicion and warrant further investigation, as it indicates a **less acidic** environment and disruption of normal lactobacilli-dominated flora. - This elevated pH suggests loss of the protective acidic environment. *>5* - A pH greater than 5 is **abnormal** for a pregnant woman and strongly suggests the presence of a **vaginal infection**, such as bacterial vaginosis, trichomoniasis, or aerobic vaginitis. - This **alkaline shift** favors the growth of pathogenic bacteria over beneficial lactobacilli, significantly increasing the risk of adverse pregnancy outcomes including preterm birth and chorioamnionitis. - Requires prompt evaluation and treatment.
Question 795: Which IUD is preferred for menorrhagia?
- A. NOVA T
- B. Cu IUD
- C. Mirena (Correct Answer)
- D. Gynefix
Explanation: ***Mirena*** - The **Mirena** IUD contains **levonorgestrel**, a progestin, which significantly reduces menstrual blood loss by causing endometrial atrophy. - It is FDA-approved for the treatment of **menorrhagia** and is highly effective in reducing heavy menstrual bleeding. *NOVA T* - **NOVA T** is a **copper IUD**, which can actually *increase* menstrual blood loss and dysmenorrhea, making it unsuitable for menorrhagia. - Copper IUDs work primarily by inducing a **local inflammatory reaction** in the uterus that is spermicidal and prevents fertilization. *Cu IUD* - Like NOVA T, **copper IUDs (Cu IUDs)** are known to exacerbate **heavy menstrual bleeding** and cramping. - They are used for contraception but are generally contraindicated in women with pre-existing menorrhagia. *Gynefix* - **Gynefix** is a frameless copper IUD designed to reduce the side effects of traditional T-shaped copper IUDs. - While it may cause less cramping than other copper IUDs, it still contains copper and can **increase menstrual flow**, making it a poor choice for menorrhagia.
Pharmacology
3 questionsWhat is a key difference between fosphenytoin and phenytoin?
Which of the following is NOT a mechanism of action of theophylline in bronchial asthma?
Omalizumab is primarily used in the treatment of which condition?
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 791: What is a key difference between fosphenytoin and phenytoin?
- A. Can be used in absence seizures
- B. Can be mixed with saline (Correct Answer)
- C. Can be given orally
- D. It is the drug of choice for myoclonic seizures
Explanation: **Can be mixed with saline** - **Fosphenytoin** is a water-soluble prodrug that is converted to phenytoin in the body; its solubility allows it to be **mixed with saline** solutions for intravenous administration, minimizing the risk of precipitation. - Unlike phenytoin, fosphenytoin's formulation avoids the need for propylene glycol, which is associated with adverse cardiovascular effects and makes phenytoin incompatible with saline. *Can be used in absence seizures* - Neither **fosphenytoin nor phenytoin** is effective for treating **absence seizures**, and they can sometimes worsen them. - **Ethosuximide** or **valproic acid** are the drugs of choice for absence seizures. *Can be given orally* - While **phenytoin** is commonly available in oral forms (capsules, chewable tablets, suspension), **fosphenytoin** is primarily designed for **parenteral administration** (intravenous or intramuscular). - Fosphenytoin is a prodrug that is rapidly converted to phenytoin *in vivo*, but it is not typically available or indicated for direct oral administration. *It is the drug of choice for myoclonic seizures* - Neither **fosphenytoin nor phenytoin** is the drug of choice for **myoclonic seizures**; they can exacerbate this type of seizure. - **Valproic acid** and **levetiracetam** are preferred treatments for myoclonic seizures due to their broader spectrum of activity.
Question 792: Which of the following is NOT a mechanism of action of theophylline in bronchial asthma?
- A. Adenosine receptor antagonism
- B. Increased histone deacetylation
- C. Phosphodiesterase inhibition
- D. Beta-2 receptor stimulation (Correct Answer)
Explanation: ***Beta-2 receptor stimulation*** - Theophylline is a **non-selective phosphodiesterase inhibitor** and an **adenosine receptor antagonist**, but it does not directly stimulate beta-2 receptors. - **Beta-2 receptor agonists** like salbutamol or formoterol are the medications that work by stimulating these receptors to cause bronchodilation. *Phosphodiesterase inhibition* - Theophylline inhibits **phosphodiesterase enzymes**, leading to an increase in intracellular **cAMP** levels. - This increase in **cAMP** promotes bronchodilation by relaxing airway smooth muscle. *Adenosine receptor antagonism* - Theophylline acts as an antagonist at **adenosine receptors**, particularly A1 and A2B. - Antagonism of adenosine receptors can reduce bronchoconstriction and inflammatory mediator release, contributing to its anti-asthmatic effects. *Increased histone deacetylation* - Theophylline, particularly at lower concentrations, increases the activity of **histone deacetylase (HDAC)**. - This action helps to **repress inflammatory gene expression**, which is a unique anti-inflammatory mechanism separate from its bronchodilatory effects.
Question 793: Omalizumab is primarily used in the treatment of which condition?
- A. Breast carcinoma
- B. Asthma (Correct Answer)
- C. Rheumatoid arthritis
- D. Chronic obstructive pulmonary disease (COPD)
Explanation: ***Asthma*** - **Omalizumab** is a **monoclonal antibody** that targets and binds to **immunoglobulin E (IgE)**, preventing it from binding to mast cells and basophils. - By reducing free IgE, omalizumab helps to prevent the release of inflammatory mediators, thereby **reducing allergic reactions and asthma symptoms**, particularly in patients with severe persistent allergic asthma. *Breast carcinoma* - **Omalizumab** is not indicated for the treatment of **breast carcinoma**; treatments for breast cancer typically involve chemotherapy, radiation, surgery, and targeted therapies specific to cancer cells. - Targeted therapies for breast cancer often focus on hormone receptors (e.g., **estrogen receptor**) or growth factor receptors (e.g., **HER2**), not IgE. *Rheumatoid arthritis* - **Omalizumab** is not used for **rheumatoid arthritis (RA)**; RA is an autoimmune disease primarily involving **T-cells and cytokines** like **TNF-alpha** and **IL-6**. - Treatment for RA typically includes **DMARDs** (disease-modifying antirheumatic drugs) and **biological agents** that target specific inflammatory pathways (e.g., **adalimumab**, **etanercept**). *Chronic obstructive pulmonary disease (COPD)* - **Omalizumab** is not indicated for **COPD**, which is primarily characterized by chronic inflammation of the airways and **emphysema**, largely caused by smoking. - COPD management focuses on bronchodilators, corticosteroids, and oxygen therapy, with no role for IgE-targeting therapy.