NEET-PG 2019 Practice Questions

Q: A child presents with the following lesion in the neck folds. The gram stain from the lesion is shown below. Comment on the diagnosis.

Erythrasma. **Erythrasma** - The image shows a **reddish-brown, finely wrinkled lesion** in an intertriginous area (neck folds), consistent with erythrasma. - The gram stain reveals **long, filamentous Gram-positive bacilli**, characteristic of *Corynebacterium minutissimum*, the causative agent of erythrasma. *Impetigo contagiosa* - This typically presents as **honey-colored crusted lesions** or vesicles, often caused by *Staphylococcus aureus* or *Streptococcus pyogenes*. - Gram stain would show **Gram-positive cocci** (clusters for staph, chains for strep), not filamentous bacilli. *Scrofuloderma* - This is a form of **cutaneous tuberculosis**, typically presenting as **nontender subcutaneous nodules** that eventually ulcerate and discharge caseous material. - Diagnosis is confirmed by identifying acid-fast bacilli or histology showing granulomas; the gram stain and lesion appearance are not consistent. *Scrum pox* - This is a **viral skin infection** (often herpes simplex virus) seen in wrestlers, presenting as **vesicular or ulcerative lesions**. - It would not show filamentous Gram-positive bacilli on a bacterial gram stain.

Q: What is the diagnosis of the lesion visible in neck folds of this child?

Intertriginous candida. ***Intertriginous candida*** - The image shows **erythema, scaling, and white satellite lesions** in a skin fold, which is characteristic of candidal intertrigo. - This condition thrives in **warm, moist environments** like neck folds of infants, often presenting with burning and itching. *SSSS* - **Staphylococcal Scalded Skin Syndrome (SSSS)** is characterized by widespread **erythema and superficial blistering**, leading to skin peeling, which is not seen here. - It usually involves a more diffuse rash and often has a **positive Nikolsky sign**, unlike the localized lesion shown. *Impetigo* - **Impetigo** typically presents with **honey-colored crusts** and is caused by bacterial infection, primarily *Staphylococcus aureus* or *Streptococcus pyogenes*. - While it can occur in skin folds, the characteristic white, cheesy appearance and satellite lesions seen in the image are not typical of impetigo. *Ecthyma* - **Ecthyma** is a more severe, ulcerative form of impetigo, characterized by **punched-out ulcers with adherent crusts** that extend into the dermis. - The lesion in the image does not show the deep ulceration or dense, dark crusts associated with ecthyma.

Q: In a patient with the following lesion on scalp, what changes are seen in the nails?

Pitting of nails. ***Pitting of nails*** - The image shows a patch of **alopecia areata** on the scalp. **Nail pitting** is the most common and characteristic nail change associated with alopecia areata, occurring in **10-66% of cases**. - Pitting appears as small depressions or **"ice-pick" marks** on the nail surface, resulting from defective nail matrix keratinization. - Other nail changes in alopecia areata include **trachyonychia (rough nails), red spotted lunulae, onycholysis**, and **Beau's lines**. *Dorsal pterygium of nails* - **Dorsal pterygium** occurs when the proximal nail fold fuses with and extends over the nail plate, creating a wing-like scar. - This is classically associated with **lichen planus, trauma, burns, vasculitis**, and **graft-versus-host disease** — **NOT alopecia areata**. - It can lead to permanent nail dystrophy or nail loss. *Azure nails* - **Azure nails** (blue nails) are typically associated with **Wilson's disease** (copper accumulation) or **minocycline use**, not alopecia areata. - They represent a blue-gray discoloration of the nail bed or lunula. *Yellow nail discolouration* - **Yellow nail syndrome** is a rare condition characterized by slow-growing, thickened, yellow nails, often associated with **lymphedema** and **respiratory problems** (pleural effusions, chronic bronchitis). - It is not linked to alopecia areata.

Q: Drug of choice for following infection (as shown in image) in a HIV patient: (NEET Pattern 2019)

Cotrimoxazole. ***Cotrimoxazole*** - The image shows numerous **dark-stained cysts** and **trophozoites** within lung tissue, characteristic of **Pneumocystis jirovecii pneumonia (PCP)**, a common opportunistic infection in HIV patients. - **Cotrimoxazole (trimethoprim-sulfamethoxazole)** is the drug of choice for the treatment and prophylaxis of PCP. *INH + Rifampicin* - This combination is used for the treatment of **tuberculosis**, characterized by **acid-fast bacilli** and granulomas, which are not seen in this image. - While TB is common in HIV patients, the morphology in the image is not consistent with Mycobacterium tuberculosis. *Doxycycline* - Doxycycline is a broad-spectrum antibiotic used for various bacterial infections, including atypical pneumonia, but it is not effective against **Pneumocystis jirovecii.** - It is also used for malaria prophylaxis and Rickettsial infections. *Azithromycin* - Azithromycin is an antibiotic primarily effective against atypical bacteria like **Mycoplasma** and **Chlamydia**, and it is used for **MAC (Mycobacterium avium complex)** prophylaxis in advanced HIV. - It has no role in the treatment of Pneumocystis jirovecii pneumonia.

Q: The following culture medium is used for the isolation of: (NEET Pattern 2019)

Legionella. ***Legionella*** - The image displays growth on **buffered charcoal yeast extract (BCYE) agar**, which is the selective medium for the isolation of *Legionella* species. - *Legionella* requires **L-cysteine** and **iron salts** for growth, which are provided in BCYE agar, making it distinctively well-suited for its isolation. *Listeria* - *Listeria* species are typically isolated on selective media such as Oxford agar or PALCAM agar, which contain **antibiotics** and **chromogenic substrates** to differentiate them from other bacteria. - While *Listeria* can grow on general purpose media, BCYE agar is not the primary selective medium for its isolation. *Escherichia* - **Escherichia coli** is a common fecal coliform that grows readily on various non-selective media like blood agar and selective/differential media such as MacConkey agar (lactose fermenter with pink colonies) or eosin methylene blue (EMB) agar (green metallic sheen colonies). - BCYE agar is not a standard medium for *Escherichia* isolation, as it lacks the necessary components for its optimal differentiation and growth. *Campylobacter* - **Campylobacter** species are **microaerophilic** and require specialized selective media like **Campy-BAP (Campylobacter Blood Agar Plate)**, Skirrow's medium, or CCDA (cefoperazone charcoal deoxycholate agar). - These media contain antibiotics to inhibit normal flora and are incubated in a microaerophilic atmosphere; BCYE agar is not used for *Campylobacter* isolation.

Q: CSF gram stain of a child suffering with meningitis is shown below. What is the causative agent? (NEET Pattern 2019)

H. influenzae. ***H. Influenzae*** - The image shows **Gram-negative rods or coccobacillary forms**, which are characteristic of *Haemophilus influenzae*. - *H. influenzae* is a common cause of **bacterial meningitis** in children, particularly before the widespread use of vaccines. *Streptococcus pneumoniae* - This bacterium would appear as **Gram-positive cocci** in pairs or short chains, which is not consistent with the image. - *Streptococcus pneumoniae* is also a common cause of meningitis but has a distinct morphological appearance. *Klebsiella pneumonia* - While *Klebsiella pneumoniae* is a Gram-negative rod, it is typically a larger, more plump rod, and less commonly a cause of **pediatric meningitis** compared to *H. influenzae*. - The morphology in the image, particularly the coccobacillary appearance, is more typical of *Haemophilus*. *Staphylococcus aureus* - This bacterium would appear as **Gram-positive cocci** in grape-like clusters, which clearly differs from the Gram-negative rods/coccobacillary forms seen in the image. - *Staphylococcus aureus* can cause meningitis, especially in cases of head trauma or neurosurgery, but its morphology is distinct.

Q: Identify the instrument? (NEET Pattern 2019)

Maddox rod. ***Maddox rod*** - The image displays a **Maddox rod**, characterized by a series of parallel, high-plus cylinders (rods) typically embedded in a red plastic disk with a handle. - This instrument is used to dissociate the eyes and convert a point source of light into a **line of light**, which is crucial for detecting and measuring heterophorias (latent deviations) and heterotropias (manifest deviations). *Maddox wing* - The **Maddox wing** is a different device used for measuring horizontal and vertical phorias at near. It consists of a septal plate that separates the visual fields of the two eyes, allowing the patient to see a set of scales with one eye and an arrow with the other. - It does not have the characteristic red parallel rods seen in the image. *Red green glasses* - **Red-green glasses** (or red-green anaglyph glasses) are used in various vision tests, such as stereopsis testing or some forms of vision therapy. - They selectively filter light, allowing one eye to see through a red filter and the other through a green filter, which is distinct from the multiple parallel rods shown. *Bagolini's striated glasses* - **Bagolini's striated glasses** are nearly plano lenses with very fine striations, designed to cause minimal disruption to vision while creating a streak of light from a point source. - They are primarily used to assess the presence and type of anomalous retinal correspondence and gross diplopia, and they do not have the prominent red rods as depicted.

Q: A 12-year-old boy develops multiple lumps in the skin. Biopsy of the lumps is shown below. What is the probable causative agent? (NEET Pattern 2019)

Cysticercus cellulosae. ***Cysticercus cellulosae*** - The presence of multiple lumps in the skin, particularly in a child, is highly suggestive of **subcutaneous cysticercosis** [1]. - **_Cysticercus cellulosae_** is the larval stage of **_Taenia solium_** (pork tapeworm), which commonly encysts in subcutaneous tissues, muscles, and the brain in humans [1]. *Cysticercus bovis* - **_Cysticercus bovis_** is the larval stage of **_Taenia saginata_** (beef tapeworm). - It primarily infects cattle and is not a common cause of subcutaneous lumps in humans. *Echinococcus granulosus* - **_Echinococcus granulosus_** causes **hydatid disease**, forming large cysts primarily in the liver and lungs [1]. - While it can form cysts in other organs, it typically presents as large, solitary cysts rather than multiple small subcutaneous lumps. *Hymenolepis Nana* - **_Hymenolepis nana_** is the **dwarf tapeworm** and is the most common cestode infection in humans. - It is an intestinal parasite and does not form cysts or lumps in the skin. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 403-405.

Q: Identify this instrument which is used for harvesting graft from a healthy area in split skin grafting:

Humby's knife. ***Humby's knife*** - The image shown is a **Humby's knife**, which is a type of **hand-held dermatome** used for harvesting split-thickness skin grafts. - It utilizes an adjustable roller to control the thickness of the graft. *Brown's dermatome* - **Brown's dermatome** (also known as a **drum dermatome**) is a mechanical, hand-held, electrically-powered dermatome. - It uses an oscillating blade and is more precise for very thin grafts but is not the instrument pictured. *Catlin amputating knife* - A **Catlin amputating knife** is a long, narrow knife primarily used for **amputations**, designed for cutting through tissue and muscle, not for skin grafting. - It has a distinct shape and purpose different from the instrument in the image. *Silver's knife* - **Silver's knife** is another type of blade used in surgery, often associated with a specific cutting technique or for specialized tissue dissection. - It is not a dermatome used for harvesting large split-thickness skin grafts.

Q: The following image shows

Encephalocele. ***Encephalocele*** - The image shows a **protrusion (sac) on the scalp** of a child, suggesting a congenital defect where brain tissue and/or meninges herniate through a defect in the skull. This is characteristic of an **encephalocele**. - **Encephaloceles** often present as a skin-covered or membranous sac, typically found along the midline of the skull, as depicted in the image. *Dermoid cyst* - A dermoid cyst is a **benign tumor** that contains mature skin structures like hair follicles and sebaceous glands. - While they can occur on the scalp, they are typically **smaller, firmer, and do not communicate with the intracranial cavity**, unlike the large, soft-appearing protrusion in the image. *Sebaceous cyst* - A sebaceous cyst, or epidermoid cyst, is a **closed sac under the skin** filled with keratin and fatty material. - These are generally **firm, mobile, and do not represent a herniation of intracranial contents**, making them unlikely given the size and appearance of the lesion. *Neurofibroma* - A neurofibroma is a **benign tumor of nerve sheath cells** that can manifest as a skin lesion or subcutaneous nodule. - While they can vary in size, they usually appear as soft, fleshy growths and are **not associated with a skull defect or herniation of brain tissue**, which is the defining feature of the lesion shown.

Question 1

A child presents with the following lesion in the neck folds. The gram stain from the lesion is shown below. Comment on the diagnosis.

Accepted Answer

Erythrasma

Answer

Impetigo contagiosa

Answer

Scrofuloderma

Answer

Scrum pox

Question 2

What is the diagnosis of the lesion visible in neck folds of this child?

Accepted Answer

Intertriginous candida

Answer

SSSS

Answer

Impetigo

Answer

Ecthyma

Question 3

In a patient with the following lesion on scalp, what changes are seen in the nails?

Accepted Answer

Pitting of nails

Answer

Azure nails

Answer

Dorsal pterygium of nails

Answer

Yellow nail discolouration

Question 4

Drug of choice for following infection (as shown in image) in a HIV patient: (NEET Pattern 2019)

Accepted Answer

Cotrimoxazole

Answer

INH+ Rifampicin

Answer

Doxycycline

Answer

Azithromycin

Question 5

The following culture medium is used for the isolation of: (NEET Pattern 2019)

Accepted Answer

Legionella

Answer

Listeria

Answer

Escherichia

Answer

Campylobacter

Question 6

CSF gram stain of a child suffering with meningitis is shown below. What is the causative agent? (NEET Pattern 2019)

Accepted Answer

H. influenzae

Answer

Streptococcus pneumoniae

Answer

Klebsiella pneumoniae

Answer

Staphylococcus aureus

Question 7

Identify the instrument? (NEET Pattern 2019)

Accepted Answer

Maddox rod

Answer

Maddox wing

Answer

Red green glasses

Answer

Bagolini's striated glasses

Question 8

A 12-year-old boy develops multiple lumps in the skin. Biopsy of the lumps is shown below. What is the probable causative agent? (NEET Pattern 2019)

Accepted Answer

Cysticercus cellulosae

Answer

Cysticercus bovis

Answer

Echinococcus granulosus

Answer

Hymenolepis Nana

Answer

Echinococcus multilocularis

Question 9

Identify this instrument which is used for harvesting graft from a healthy area in split skin grafting:

Accepted Answer

Humby's knife

Answer

Brown's dermatome

Answer

Catlin amputating knife

Answer

Silver's knife

Question 10

The following image shows

Accepted Answer

Encephalocele

Answer

Dermoid cyst

Answer

Sebaceous cyst

Answer

Neurofibroma

NEET-PG 2019

Dermatology

Internal Medicine

Microbiology

Ophthalmology

Pathology

Surgery