Dermatology
4 questionsIn which condition is an ulceronecrotic nodule typically observed?
What is the most likely diagnosis for a 15 mm hyperpigmented lesion on the shoulder that is enlarging and has hair growing from it?
Treatment of dermatitis herpetiformis:
What is the most common trigger associated with erythema multiforme?
NEET-PG 2013 - Dermatology NEET-PG Practice Questions and MCQs
Question 1351: In which condition is an ulceronecrotic nodule typically observed?
- A. Lucio's leprosy (Correct Answer)
- B. Lepromatous leprosy
- C. Indeterminate leprosy
- D. Histoid leprosy
Explanation: ***Lucio's leprosy*** - This is a rare, diffuse variant of **lepromatous leprosy** characterized by widespread, diffuse infiltration of the skin without distinct nodules. - The distinctive feature is the occurrence of **necrotizing vasculitis**, leading to painful, irregular ulcers and scars, known as **Lucio phenomenon** or erythema necroticans. *Lepromatous leprosy* - Characterized by **multiple, symmetrical nodules**, plaques, and diffuse infiltration, but typically without the profound ulceronecrotic changes seen in Lucio's leprosy. - The immune response is weak, leading to high bacterial load and widespread involvement, but usually not spontaneous ulceration. *Indeterminate leprosy* - This is an **early, undifferentiated form** of leprosy, characterized by a single or a few hypopigmented or erythematous macules. - Distinct nodules or ulceronecrotic lesions are not a feature of indeterminate leprosy, as the disease has not yet progressed to develop specific clinical manifestations. *Histoid leprosy* - A rare variant of lepromatous leprosy that presents with **cutaneous nodules** and papules that often resemble dermatofibromas or xanthomas. - These nodules are firm, smooth, and have a unique histological appearance, but they do not typically undergo spontaneous ulceronecrotic changes like those in Lucio's leprosy.
Question 1352: What is the most likely diagnosis for a 15 mm hyperpigmented lesion on the shoulder that is enlarging and has hair growing from it?
- A. Melanocytic nevus
- B. Becker nevus (Correct Answer)
- C. Sebaceous nevus
- D. Comedo nevus
Explanation: ***Correct: Becker nevus*** This diagnosis is supported by the description of a **hyperpigmented lesion** that is **enlarging** and has **hair growing from it**, typically appearing during adolescence or young adulthood. **Becker nevus** often presents as an **irregular, hyperpigmented patch**, usually on the shoulder or upper trunk, and is characteristically associated with **hypertrichosis** (increased terminal hair growth). The combination of location (shoulder), enlargement, and hair growth in a 15 mm lesion is classic for Becker nevus. *Incorrect: Melanocytic nevus* While **melanocytic nevi** are hyperpigmented, they typically do not continue to **enlarge significantly** after childhood and generally do not develop new onset **hypertrichosis** as a primary feature. The size (15 mm) and progressive growth combined with hair development are more characteristic of a Becker nevus than a common melanocytic nevus. *Incorrect: Sebaceous nevus* **Sebaceous nevi** are typically **yellow-orange to tan, waxy plaques**, often on the scalp or face, with a cobblestone or papillomatous texture. They are not primarily characterized by **hyperpigmentation** and terminal hair growth, but rather by sebaceous gland proliferation. *Incorrect: Comedo nevus* A **comedo nevus** presents as a linear or unilateral group of **dilated follicular openings** filled with keratinous material, resembling blackheads. It is not characterized by diffuse **hyperpigmentation** or the increased terminal hair growth described in this case.
Question 1353: 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 1354: 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.
Internal Medicine
3 questionsWhich type of leprosy does not involve nerve damage?
A man with pain during defecation, no gastrointestinal symptoms, and ulcers extending into the anal canal. Diagnosis?
Which of the following is a characteristic feature of Granulomatosis with polyangiitis?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 1351: Which type of leprosy does not involve nerve damage?
- A. Indeterminate leprosy (Correct Answer)
- B. Borderline tuberculoid leprosy
- C. Tuberculoid leprosy
- D. Lepromatous leprosy
Explanation: ***Indeterminate leprosy*** - This is the earliest form of leprosy and often presents with only a **single skin lesion** and no demonstrable nerve damage. - Due to the minimal immune response, it can be difficult to classify and may progress to other forms if left untreated. *Tuberculoid leprosy* - Characterized by a **strong cell-mediated immune response** to *Mycobacterium leprae*, leading to significant nerve involvement [1]. - Patients typically present with well-demarcated, **hypopigmented patches** with definite **sensory loss** due to nerve damage [1]. *Borderline tuberculoid leprosy* - This form sits between tuberculoid and borderline lepromatous leprosy, showing features of both, including **nerve involvement** [2]. - It presents with a few to several skin lesions that are usually smaller and less clearly defined than tuberculoid lesions, often with **palpable nerves** and mild sensory loss [2]. *Lepromatous leprosy* - Characterized by a **weak or absent cell-mediated immune response**, leading to widespread bacterial proliferation and extensive nerve damage, often symmetrical [1]. - Patients show numerous, poorly defined skin lesions, nodules, and severe nerve involvement, which can result in significant **deformities** [2].
Question 1352: A man with pain during defecation, no gastrointestinal symptoms, and ulcers extending into the anal canal. Diagnosis?
- A. Cytomegalovirus (CMV)
- B. Gonococcal infection
- C. Genital herpes (Correct Answer)
- D. HIV infection
Explanation: Herpes simplex virus (HSV) infection of the anal canal is characterized by lesions that present as painful ulcers [1]. Direct extension into the anal canal is common in individuals with receptive anal intercourse or autoinoculation, often causing symptoms such as anal or rectal pain [1]. CMV proctitis typically causes more diffuse inflammation, often with bloody stools, diarrhea, and abdominal pain, which are not described in this case. While CMV can cause ulcers, they are usually shallow and often associated with immunocompromised states. Gonococcal proctitis often presents with purulent anal discharge, rectal pain, itching, and tenesmus, but typically without deep ulcerations. HIV infection can cause various anorectal complications, including aphthous ulcers, but isolated anal ulcers and defecation pain would prompt investigation into sexually transmitted infections like herpes as a more direct cause.
Question 1353: Which of the following is a characteristic feature of Granulomatosis with polyangiitis?
- A. Nasal polyp
- B. Perforated nasal septum (Correct Answer)
- C. Persistent sinusitis
- D. Collapse of nasal bridge
Explanation: ***Perforated nasal septum*** - **Granulomatosis with polyangiitis (GPA)**, previously known as **Wegener's granulomatosis**, is characterized by **granulomatous inflammation** and **vasculitis** of small to medium-sized vessels, particularly affecting the upper and lower respiratory tracts, and the kidneys [1]. - Damage to the nasal cartilage and bone due to inflammation and vasculitis can lead to a **perforation of the nasal septum**, which is a classic feature. *Nasal polyp* - While nasal polyps can occur in inflammatory conditions, they are **not a specific or highly characteristic feature** of Granulomatosis with polyangiitis compared to septal perforation. - **Allergic rhinitis** or **chronic rhinosinusitis** are more commonly associated with nasal polyps. *Persistent sinusitis* - **Persistent sinusitis** (rhinosinusitis) is a very common initial manifestation of Granulomatosis with polyangiitis due to upper airway inflammation. - However, it's a **less specific finding** than a perforated septum, as sinusitis can be caused by many other conditions. *Collapse of nasal bridge* - **Collapse of the nasal bridge**, also known as a **saddle nose deformity**, can occur in advanced or destructive cases of Granulomatosis with polyangiitis due to extensive cartilage and bone destruction. - While possible, a **perforated nasal septum often precedes** or is a more direct, earlier indicator of the destructive process in the nose.
Pharmacology
3 questionsWhich drug is most commonly associated with causing exanthema?
Which drug is most commonly associated with causing fixed drug eruptions?
Which 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 1351: Which drug is most commonly associated with causing exanthema?
- A. Atropine
- B. Phenytoin
- C. Sulfonamide (Correct Answer)
- D. All of the options
Explanation: ***Sulfonamide*** - **Sulfonamides** are among the **most common causes** of drug-induced exanthema (maculopapular/morbilliform rash). - They account for a significant proportion of cutaneous adverse drug reactions, with exanthema being the most frequent presentation. - The mechanism typically involves a **delayed hypersensitivity reaction** (Type IV) to the drug or its metabolites. - **Classic presentation:** Symmetrical, erythematous, maculopapular rash appearing 7-14 days after drug initiation. *Phenytoin* - **Phenytoin** can cause exanthematous eruptions, but it is more notably associated with **severe cutaneous adverse reactions** such as: - **DRESS syndrome** (Drug Reaction with Eosinophilia and Systemic Symptoms) - **Stevens-Johnson syndrome (SJS)** and **Toxic Epidermal Necrolysis (TEN)** - While exanthema can occur, **sulfonamides** are more frequently implicated in simple morbilliform rashes. *Atropine* - **Atropine** is an anticholinergic agent primarily causing **predictable pharmacological effects**: - Dry mouth, mydriasis, tachycardia, urinary retention - **Allergic skin reactions** with atropine are rare and not a characteristic adverse effect. - Atropine is **not recognized** as a common cause of exanthema. *All of the options* - This is incorrect because **atropine** is not commonly associated with exanthema. - While both sulfonamides and phenytoin can cause exanthema, only **sulfonamides** are considered among the **most common** causes.
Question 1352: Which drug is most commonly associated with causing fixed drug eruptions?
- A. Aminoglycoside
- B. Sulfonamide (Correct Answer)
- C. Erythromycin
- D. None of the options
Explanation: ***Sulfonamide*** - **Sulfonamides**, particularly **sulfamethoxazole-trimethoprim**, are frequently implicated in causing fixed drug eruptions. - A fixed drug eruption characteristically recurs at the **same cutaneous site** each time the offending drug is administered. *Aminoglycoside* - **Aminoglycosides** are broad-spectrum antibiotics known for potential **ototoxicity** and **nephrotoxicity**. - While they can cause various adverse reactions, fixed drug eruptions are **not a common association** with this drug class. *Erythromycin* - **Erythromycin** is a macrolide antibiotic primarily associated with **gastrointestinal side effects**, such as nausea and abdominal cramping. - Although drug eruptions can occur, fixed drug eruptions are **not typically linked** to erythromycin. *None of the options* - This option is incorrect because **sulfonamides** are well-documented causes of fixed drug eruptions. - Therefore, there is a specific drug class listed that is strongly associated with this condition.
Question 1353: 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.