NEET-PG 2012 - Dermatology Practice Questions

Q: What is the maximum cumulative dose of isotretinoin for acne treatment?

120-150 mg/kg. ***120-150 mg/kg*** - The goal of **isotretinoin cumulative dosing** is to achieve long-term remission and reduce the risk of relapse. - A cumulative dose in the range of **120-150 mg/kg** has been shown to optimize treatment outcomes for severe or recalcitrant acne. *30-60 mg/kg* - This range is typically considered too low to achieve the optimal **cumulative dose** for sustained remission in severe acne. - Doses within this range might be used in some cases for milder forms of acne or in patients with significant side effects, but not as the standard maximum. *60-90 mg/kg* - While this is closer to an effective cumulative dose, it still often falls short of the recommended range for maximizing the long-term efficacy and reducing relapse rates in patients with severe forms of acne. - Studies suggest that higher cumulative doses correlate with better treatment success and fewer recurrences. *90-120 mg/kg* - This range is often considered a minimal target for a **cumulative dose**, especially at the higher end of the range (120 mg/kg). - While effective for many patients, aiming for the upper end (120-150 mg/kg) often provides a more robust and durable response, particularly in more severe or nodular acne.

Q: What is the best method to treat a large port-wine stain?

Pulsed dye laser. ***Pulsed dye laser*** - The **pulsed dye laser (PDL)** is considered the **gold standard** for treating port-wine stains due to its specific targeting of hemoglobin in the dilated capillaries without damaging surrounding tissue. - This treatment involves multiple sessions to progressively lighten the stain and prevent complications such as **nodularity** and **tissue hypertrophy**. *Radiotherapy* - **Radiotherapy** is generally not recommended for port-wine stains due to its potential for **scarring**, **pigment changes**, and risk of **malignancy**. - It is an aggressive treatment typically reserved for **cancerous conditions** or severe proliferative vascular lesions not amenable to other treatments. *Tattooing* - **Tattooing** involves injecting skin-colored pigments into the lesion to camouflage it, but it does not treat the underlying vascular abnormality. - This method can result in an **artificial appearance**, **uneven coverage**, and potential for **allergic reactions** or infections. *Excision with skin grafting* - **Surgical excision** of a large port-wine stain would result in a **significant scar** and require **skin grafting**, which carries risks of graft failure, poor aesthetic outcome, and color mismatch. - This method is generally reserved for very small, localized lesions or those with significant **nodular hypertrophy** that cannot be effectively managed by laser therapy.

Q: Richner-Hanhart syndrome is characterized by which of the following?

Ocular and cutaneous features. ***Ocular and cutaneous features*** - **Richner-Hanhart syndrome**, also known as **Tyrosinemia type II**, is characterized by the classic triad of **painful hyperkeratotic plaques** on the palms and soles (cutaneous features), **corneal ulcers** or **dendritic keratitis** (ocular features), and **variable neurological involvement**. - These features arise from the accumulation of **tyrosine** due to a deficiency of the enzyme **hepatic tyrosine aminotransferase (TAT)**. - The **ocular and cutaneous manifestations** are the hallmark features that define this syndrome. *Autosomal dominant* - Richner-Hanhart syndrome is inherited in an **autosomal recessive** pattern, meaning two copies of the defective gene (TAT gene on chromosome 16) are required for the condition to manifest. - An **autosomal dominant** inheritance pattern would mean only one copy of the defective gene is sufficient to cause the disorder. *Associated with abnormality in lipid metabolism* - The syndrome is an inborn error of **amino acid metabolism**, specifically involving **tyrosine**, not lipid metabolism. - Diseases associated with abnormality in **lipid metabolism** include conditions like Gaucher disease, Niemann-Pick disease, or Fabry disease. *Never associated with neurological involvement* - This is **incorrect**. **Neurological involvement** including intellectual disability, developmental delay, seizures, and behavioral problems occurs in **30-50% of cases**. - The accumulation of **tyrosine** and its metabolites (particularly tyrosine crystals) can be **neurotoxic**, leading to varying degrees of neurological impairment. - Early dietary restriction of tyrosine and phenylalanine can prevent or minimize neurological complications.

Q: Loss of intercellular cohesion between keratinocytes is referred to as?

Acantholysis. ***Acantholysis*** - This term specifically refers to the **loss of cohesion between keratinocytes** in the epidermis due to the breakdown of desmosomal attachments. - It is a hallmark feature of several **blistering skin diseases**, such as pemphigus. *Acanthosis* - This refers to the **thickening of the stratum spinosum** (prickle cell layer) of the epidermis, often due to an increase in the number of keratinocytes. - It is seen in conditions like **psoriasis** and seborrheic keratosis, but does not involve a loss of intercellular cohesion. *Keratinolysis* - This term describes the **breakdown or dissolution of keratin**, which is the primary structural protein of the epidermis. - While keratinocytes produce keratin, keratinolysis itself is not the specific term for loss of cohesion between these cells. *Spongiosis* - This is defined as **intercellular edema** (fluid accumulation) within the epidermis, especially prominent in the stratum spinosum. - It leads to the widening of intercellular spaces and stretching of desmosomes, but the cells generally remain attached, unlike in acantholysis.

Q: Which of the following is NOT a characteristic of dermatophytosis?

Subdermal infection. ***Subdermal infection*** - Dermatophytosis, or **ringworm**, is characterized by infection of the **superficial keratinized tissues** (skin, hair, nails) and does not typically extend into the subdermal layers. - While fungal infections can be systemic or deep, dermatophytes specifically are restricted to the **stratum corneum** and other dead keratinized structures. *Scaly skin* - **Scaling** is a very common characteristic of dermatophyte infections due to the fungus proliferating within the **stratum corneum**, leading to increased epidermal turnover and shedding. - The scaling can be fine or coarse, often presenting in an **annular (ring-like)** pattern. *Itchy skin* - **Pruritus (itching)** is a prominent symptom of dermatophytosis, often leading patients to seek medical attention. - The itching can range from mild to severe, contributing to discomfort and potential secondary skin excoriations. *Superficial infection* - Dermatophytosis is by definition a **superficial fungal infection**, meaning it is confined to the outermost layers of the skin, hair, and nails. - These fungi produce enzymes such as **keratinases** that allow them to digest keratin, but they generally do not invade viable tissue below the epidermis.

Q: Muir–Torre syndrome shows

Sebaceous gland tumors. ***Sebaceous gland tumors*** - **Muir-Torre syndrome** is a genetic condition characterized by the presence of at least one **sebaceous gland tumor** (adenoma, epithelioma, or carcinoma) and at least one internal malignancy. - It is considered a variant of **Lynch syndrome (hereditary nonpolyposis colorectal cancer - HNPCC)**, stemming from germline mutations in **DNA mismatch repair genes**. *Intestinal polyps (associated with familial adenomatous polyposis)* - While Lynch syndrome (to which Muir-Torre is related) does involve an increased risk of colorectal cancer, **multiple intestinal polyps** are the hallmark of **Familial Adenomatous Polyposis (FAP)**. - FAP is caused by a mutation in the **APC gene**, distinct from the mismatch repair gene mutations seen in Muir-Torre syndrome. *Lisch nodules (associated with Neurofibromatosis type 1)* - **Lisch nodules** are benign **iris hamartomas** typically found in patients with **Neurofibromatosis type 1 (NF1)**. - NF1 is a neurocutaneous disorder caused by a mutation in the **NF1 gene**, presenting with café-au-lait spots, neurofibromas, and optic gliomas, which are unrelated to Muir-Torre syndrome. *Hyperelastic joints (associated with Ehlers-Danlos syndrome)* - **Hyperelasticity of joints** and skin is a characteristic feature of **Ehlers-Danlos syndrome (EDS)**, a group of heritable disorders affecting connective tissue. - EDS is caused by defects in **collagen synthesis or processing**, and its clinical manifestations are distinct from the mucocutaneous and internal malignancies seen in Muir-Torre syndrome.

Q: Which of the following is NOT a feature of atopic dermatitis?

Darier’s Sign. ***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

Q: Which of the following statements about spider telangiectasia is false?

More common in males. ***More common in males*** - This statement is **FALSE** because spider telangiectasias (spider nevi/spider angiomas) are more commonly observed in **females**, often due to hormonal influences like **estrogen**. - They are frequently associated with conditions such as **pregnancy**, **oral contraceptive use**, or **chronic liver disease**, highlighting a female predominance. - The estrogen-dependent nature explains their higher prevalence in women of reproductive age. *Can be caused by trauma* - This statement is **TRUE** in a broader sense, though classical spider telangiectasias are primarily hormonally-mediated rather than traumatic. - While **simple telangiectasias** can develop after localized trauma or repeated pressure, spider telangiectasias have a characteristic morphology (central arteriole with radiating vessels) and are typically associated with **estrogen excess** or **liver disease**. - For exam purposes, this is considered a true statement as telangiectatic vessels can be influenced by local factors. *Light therapy for treatment* - This statement is **TRUE**. **Laser therapy**, specifically **pulsed dye laser (PDL)** or **intense pulsed light (IPL)**, is the most effective treatment for spider telangiectasias. - The laser selectively targets **hemoglobin** in the dilated vessels, causing photocoagulation and vessel obliteration, leading to excellent cosmetic results. *May be associated with liver disease* - This statement is **TRUE**. Spider telangiectasias are a well-recognized cutaneous manifestation of **chronic liver disease**, especially **cirrhosis**. - Impaired hepatic function leads to decreased **estrogen metabolism** (hyperestrogenemia), contributing to the development of these vascular lesions. - They are one of the stigmata of chronic liver disease, along with palmar erythema and gynecomastia.

Q: Phrynoderma is primarily associated with a deficiency of which of the following?

Vitamin A. ***Vitamin A*** - **Phrynoderma** (toad skin) has been **classically attributed to vitamin A deficiency** in traditional medical literature and was the accepted answer in historical examinations. - It presents as **follicular hyperkeratosis** with dry, scaly, rough skin having prominent hair follicles with a sandpaper-like texture. - However, **modern evidence** suggests phrynoderma is a **multifactorial condition** often involving **multiple nutritional deficiencies**, with vitamin A being one important contributor among others. *Essential fatty acid* - Deficiency of **essential fatty acids** (linoleic and alpha-linolenic acid) causes **skin dryness, flakiness, and follicular hyperkeratosis**. - **Recent studies** indicate EFA deficiency may play a **significant role** in phrynoderma, particularly in developing countries where multiple nutritional deficiencies coexist. - The clinical presentation can closely mimic vitamin A deficiency-related skin changes. *Vitamin D* - Deficiency of **vitamin D** primarily causes **rickets** in children and **osteomalacia** in adults with bone pain, muscle weakness, and skeletal deformities. - While vitamin D has roles in skin health, its deficiency does not directly cause the follicular hyperkeratosis characteristic of phrynoderma. *Niacin* - **Niacin (vitamin B3)** deficiency causes **pellagra** with the classic \"3 Ds\": **dermatitis, diarrhea, and dementia**. - Pellagra dermatitis is typically **symmetrical in sun-exposed areas** with redness, scaling, and hyperpigmentation—distinctly different from the follicular pattern of phrynoderma.

Question 1

What is the maximum cumulative dose of isotretinoin for acne treatment?

Accepted Answer

120-150 mg/kg

Answer

30-60 mg/kg

Answer

60-90 mg/kg

Answer

90-120 mg/kg

Question 2

What is the best method to treat a large port-wine stain?

Accepted Answer

Pulsed dye laser

Answer

Radiotherapy

Answer

Excision with skin grafting

Answer

Tattooing

Question 3

Richner-Hanhart syndrome is characterized by which of the following?

Accepted Answer

Ocular and cutaneous features

Answer

Autosomal dominant

Answer

Associated with abnormality in lipid metabolism

Answer

Never associated with neurological involvement

Question 4

Which of the following statements about lepromatous leprosy is true?

Accepted Answer

Lepromatous leprosy typically presents with multiple cutaneous lesions.

Answer

Thickened peripheral nerves are a common feature.

Answer

Erythema nodosum leprosum occurs in less than 50% of cases.

Answer

The lepromin test is usually negative or weakly positive.

Question 5

Loss of intercellular cohesion between keratinocytes is referred to as?

Accepted Answer

Acantholysis

Answer

Acanthosis

Answer

Keratinolysis

Answer

Spongiosis

Question 6

Which of the following is NOT a characteristic of dermatophytosis?

Accepted Answer

Subdermal infection

Answer

Scaly skin

Answer

Itchy skin

Answer

Superficial infection

Question 7

Muir–Torre syndrome shows

Accepted Answer

Sebaceous gland tumors

Answer

Intestinal polyps

Answer

Lisch nodules

Answer

Hyperelastic joints

Question 8

Which of the following is NOT a feature of atopic dermatitis?

Accepted Answer

Darier’s Sign

Answer

Dennie-Morgan fold

Answer

Hyperlinearity of palms

Answer

Hertoghe’s sign

Question 9

Which of the following statements about spider telangiectasia is false?

Accepted Answer

More common in males

Answer

Light therapy for treatment

Answer

May be associated with liver disease

Answer

Can be caused by trauma

Question 10

Phrynoderma is primarily associated with a deficiency of which of the following?

Accepted Answer

Vitamin A

Answer

Essential fatty acid

Answer

Vitamin D

Answer

Niacin

NEET-PG 2012 — Dermatology