Dermatological Procedures — MCQs

Dermatological Procedures Indian Medical PG Practice Questions and MCQs

Question 31: Which of the following are correct for managing hypertrophic scars? 1. Silicone gel sheeting 2. Intralesional steroid injections 3. Vitamin A gel applications 4. Laser treatment Select the answer using the code given below.

A. 1, 3 and 4
B. 1, 2 and 3
C. 1, 2 and 4 (Correct Answer)
D. 2, 3 and 4

Explanation: ***1, 2 and 4*** - **Silicone gel sheeting**, **intralesional steroid injections**, and **laser treatment** are all established and effective methods for managing hypertrophic scars. - Silicone gel helps to hydrate the scar, reduce collagen synthesis, and decrease itching, while steroids reduce inflammation and collagen production, and lasers can help to improve scar texture and color. *1, 3 and 4* - This option incorrectly includes **Vitamin A gel applications** as a primary treatment. While retinoids can have some skin benefits, they are not a first-line or well-established treatment for hypertrophic scars. - **Silicone gel sheeting** and **laser treatment** are indeed effective, but the inclusion of Vitamin A makes this option less accurate. *1, 2 and 3* - This option also incorrectly includes **Vitamin A gel applications**. While **silicone gel sheeting** and **intralesional steroid injections** are effective, Vitamin A is not a standard treatment for hypertrophic scars. - The primary methods for managing hypertrophic scars focus on reducing collagen production and inflammation, which Vitamin A gel does not effectively address in this context. *2, 3 and 4* - This option correctly includes **intralesional steroid injections** and **laser treatment**, but it again incorrectly includes **Vitamin A gel applications** and omits **silicone gel sheeting**, which is a widely recommended and often first-line treatment. - Omitting **silicone gel sheeting** significantly weakens the effectiveness of this combination as a comprehensive management strategy.

Question 32: Match the following woods lamp findings: 1. Erythrasma, 2. Pityriasis versicolor, 3. Tinea capitis, 4. Vitiligo || a. Yellow b. Coral red fluorescence c. Pink d. Green e. Milky white

A. 1-d, 2-a, 3-c, 4-e
B. 1-b, 2-a, 3-d, 4-e (Correct Answer)
C. 1-a, 2-c, 3-e, 4-d
D. 1-b, 2-d, 3-a, 4-c

Explanation: ***1-b, 2-a, 3-d, 4-e*** - **Erythrasma** is caused by *Corynebacterium minutissimum* and produces **porphyrins** that fluoresce **coral red** under a Wood's lamp [1]. - **Pityriasis versicolor** is caused by *Malassezia furfur* and typically fluoresces **yellow to yellowish-green** [2]. - **Tinea capitis** (especially due to *Microsporum* species) shows **green fluorescence** of infected hairs. - **Vitiligo** lesions, due to a complete absence of melanin, appear as **milky white** or bright white areas under a Wood's lamp [3]. *1-d, 2-a, 3-c, 4-e* - This option incorrectly states that Erythrasma fluoresces green. Green fluorescence is characteristic of *Microsporum* species causing **Tinea capitis**. - Additionally, Tinea capitis is incorrectly associated with pink fluorescence, which is not a typical finding. *1-a, 2-c, 3-e, 4-d* - This option incorrectly states that Erythrasma fluoresces yellow. Yellow fluorescence is associated with **Pityriasis versicolor** [2]. - It also incorrectly assigns milky white fluorescence to Tinea capitis and green fluorescence to Vitiligo. *1-b, 2-d, 3-a, 4-c* - This option incorrectly associates Pityriasis versicolor with green fluorescence. While some variations exist, **yellow** is the more characteristic finding [2]. - It also incorrectly links Tinea capitis to yellow fluorescence and Vitiligo to pink, which are not typical Wood's lamp findings for these conditions.

Question 33: Wood's lamp is not used for diagnosing:

A. Lichen planus (Correct Answer)
B. Pityriasis versicolor
C. Porphyria
D. Vitiligo

Explanation: ***Lichen planus*** - **Wood's lamp** is generally not used for diagnosing **lichen planus** as the lesions typically do not fluoresce. - Diagnosis of lichen planus relies on its characteristic **violaceous, polygonal, pruritic papules and plaques** and often confirmed by **biopsy**. *Pityriasis versicolor* - **Wood's lamp** is useful for **pityriasis versicolor**, causing it to fluoresce a **yellowish-green or coppery-orange** color due to metabolic byproducts of *Malassezia* fungi. - This characteristic fluorescence helps in differentiating lesions from other skin conditions and in identifying subclinical involvement. *Porphyria* - **Wood's lamp** can be used to detect **reddish-pink fluorescence of urine** or skin in patients with **porphyria cutanea tarda** due to the accumulation of porphyrins. - This fluorescence is a key diagnostic indicator in certain types of **porphyria**, particularly those affecting the skin. *Vitiligo* - **Wood's lamp** enhances the contrast between depigmented and normally pigmented skin, making **vitiligo** lesions appear **bright bluish-white** due to the absence of melanin. - It is particularly useful for detecting subtle or small lesions of **vitiligo**, especially in individuals with lighter skin tones.

Question 34: Diascopy is very helpful in the diagnosis of:

A. Lupus vulgaris
B. Cutaneous vasculitis
C. Nevus anaemicus
D. All of the options (Correct Answer)

Explanation: ***All of the options*** - Diascopy is a diagnostic technique using a glass slide to apply pressure on skin lesions, helping differentiate between **vascular (erythematous)** and **non-vascular lesions** and revealing underlying pathology. - It is particularly helpful in diagnosing **lupus vulgaris**, **cutaneous vasculitis**, and **nevus anaemicus**. *Lupus vulgaris* - Shows pathognomonic **apple-jelly nodules** on diascopy due to granulomatous inflammation. - When pressed with a glass slide, the lesion reveals a characteristic **translucent yellowish-brown ("apple jelly") color** from tuberculoid granulomas. *Cutaneous vasculitis* - Diascopy differentiates **purpura (extravasated blood)** from simple erythema. - **Non-blanching purpura** indicates intravascular hemorrhage from vessel wall damage, a key feature of vasculitis. - Blanching erythema would suggest vasodilation rather than true vasculitis. *Nevus anaemicus* - Diascopy causes the pale lesion to **disappear or blend** with surrounding blanched normal skin. - This occurs because normal surrounding vessels constrict under pressure, matching the baseline pale appearance of the nevus. - This helps distinguish it from other hypopigmented lesions like vitiligo (which remains visible on diascopy).

Question 35: Chemical peeling is indicated in all of the following except

A. Melasma
B. Acne vulgaris
C. Photoaging
D. Lichen planus (Correct Answer)

Explanation: ***Lichen planus*** - Chemical peels are generally **contraindicated** in active inflammatory conditions like **lichen planus**, as they can worsen the inflammation or trigger a Koebner phenomenon. - While chemical peels can address post-inflammatory hyperpigmentation, they should not be used during the active phase of lichen planus due to the risk of exacerbation. *Melasma* - **Melasma** is a common indication for chemical peels, particularly superficial and medium-depth peels, to reduce hyperpigmentation. - Peels containing agents like **glycolic acid**, salicylic acid, or trichloroacetic acid are often used to lighten melanin deposits. *Acne vulgaris* - Chemical peels are effective in treating **acne vulgaris** by exfoliating the skin, reducing comedones, and improving overall skin texture. - **Salicylic acid peels** are particularly useful due to their lipophilic nature, allowing them to penetrate and clean pores. *Photoaging* - **Photoaging**, characterized by fine lines, wrinkles, and dyspigmentation from sun exposure, is a primary indication for chemical peels. - Peels can promote **collagen remodeling** and help achieve a more even skin tone and smoother texture.

Question 36: Chemical peeling is done by all except -

A. Trichloroacetic acid
B. Carbolic acid
C. Kojic acid
D. Phosphoric acid (Correct Answer)

Explanation: ***Phosphoric acid*** - **Phosphoric acid** is primarily used in **dentistry as an etching agent** for dental restorations and in food as an additive for tartness, **NOT for chemical peels**. - It does not possess the dermatological exfoliating or regenerating properties required for chemical peeling. - Standard chemical peeling agents include **glycolic acid, salicylic acid, TCA, and phenol**. *Trichloroacetic acid (TCA)* - **TCA** is a well-established agent used for **medium to deep chemical peels**, depending on concentration (10-50%). - It works by **coagulating epidermal and dermal proteins**, leading to controlled skin exfoliation and regeneration. *Carbolic acid (Phenol)* - **Carbolic acid (phenol)** is used for **deep chemical peels** (Baker-Gordon peel), particularly for severe photoaging, deep wrinkles, and scars. - It causes protein denaturation and deep dermal necrosis, leading to substantial exfoliation and collagen remodeling. *Kojic acid* - **Kojic acid** is primarily a **skin-lightening agent** that inhibits tyrosinase enzyme, reducing melanin production for treating hyperpigmentation. - While it may be incorporated into some topical formulations, **it is NOT a chemical peeling agent** — it does not cause controlled skin necrosis or exfoliation like true peeling agents (TCA, phenol, glycolic acid, salicylic acid). - Some sources may mention its use in superficial peels, but it is NOT considered a standard chemical peeling agent in dermatological practice.

Question 37: Which of the following are side effects of using argon laser?

A. Hypopigmentation
B. Crusting
C. Keloid formation
D. All of the options (Correct Answer)

Explanation: ***All of the options*** - **Argon laser** targets hemoglobin and melanin, making it effective for vascular lesions but also carries a risk of pigmentary changes, scar formation, and local tissue reactions. - **Hypopigmentation**, **crusting**, and **keloid formation** are all recognized potential side effects due to its thermal destructive mechanism. *Hypopigmentation* - This side effect occurs due to the **non-selective absorption** of argon laser energy by **melanin** in the epidermis, leading to destruction of melanocytes. - It results in lighter patches of skin in the treated area, especially problematic in darker skin types. *Crusting* - **Crusting** is a common immediate post-treatment effect following argon laser therapy, caused by tissue damage and subsequent inflammation and exudation. - It indicates surface epithelial damage and typically resolves as the skin heals, but proper wound care is essential to prevent infection. *Keloid formation* - **Keloid formation** is a risk with argon laser treatment, particularly in individuals prone to abnormal scarring. - The thermal injury caused by the laser can trigger an exaggerated wound healing response, leading to raised, fibrous scars that extend beyond the original treated area.

Question 38: Compare the following treatment modalities for actinic keratoses: 1. Cryotherapy a. Field treatment, high clearance 2. 5-fluorouracil b. Targets single lesions 3. Photodynamic therapy c. Requires multiple office visits

A. 1-a, 2-b, 3-c
B. 1-b, 2-c, 3-a
C. 1-b, 2-a, 3-c (Correct Answer)
D. 1-c, 2-a, 3-b

Explanation: ***1-b, 2-a, 3-c*** - This option correctly matches **cryotherapy** with targeting **single lesions**, **5-fluorouracil** with **field treatment** and **high clearance**, and **photodynamic therapy** with requiring **multiple office visits**. - **Cryotherapy** is a localized treatment, **5-fluorouracil** is applied broadly to treat multiple lesions, and **PDT** involves an initial sensitizer application followed by light exposure. *1-a, 2-b, 3-c* - This option incorrectly states **cryotherapy** as a field treatment with high clearance because **cryotherapy** is primarily used for **individual lesions**. - It also inaccurately assigns **5-fluorouracil** to targeting single lesions, as **5-FU** is known for its effectiveness as a **field treatment**. *1-b, 2-c, 3-a* - This option incorrectly associates **5-fluorouracil** with requiring multiple office visits. While it is applied over several days or weeks, these are typically at-home treatments, not numerous in-office visits. - It also incorrectly matches **photodynamic therapy** with field treatment and high clearance, whereas while PDT is a field treatment, its clearance rates can vary, and it usually requires multiple visits. *1-c, 2-a, 3-b* - This response inaccurately suggests that **cryotherapy** requires multiple office visits, when in fact it is often a **single-session treatment** per lesion. - It also wrongly correlates **photodynamic therapy** with targeting single lesions, as **PDT** is typically applied over a **broader area** for field treatment.

Question 39: What is the best method to treat a large port-wine stain?

A. Radiotherapy
B. Excision with skin grafting
C. Pulsed dye laser (Correct Answer)
D. Tattooing

Explanation: ***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.

Question 40: What is the first-line treatment for melasma?

A. Laser therapy
B. Topical hydroquinone (Correct Answer)
C. Chemical peels
D. Microdermabrasion

Explanation: ***Topical hydroquinone*** - **Topical hydroquinone** (2-4%) is the **most effective single-agent treatment** among the given options, serving as the gold standard for melasma by inhibiting **tyrosinase enzyme** and melanin production. - Demonstrates **highest efficacy rates** (60-80% improvement) when combined with strict sun protection, making it both first-line and most effective monotherapy choice. *Laser therapy* - Carries **high risk of paradoxical darkening** and post-inflammatory hyperpigmentation, especially in darker skin types common in melasma patients. - Requires **specialized expertise** and should only be considered as adjunctive therapy after optimizing topical treatments, not as primary treatment. *Chemical peels* - Provide **variable and inconsistent results** as monotherapy, typically requiring multiple sessions with unpredictable outcomes. - Risk of **post-inflammatory hyperpigmentation** particularly in Fitzpatrick skin types IV-VI, making them less reliable than hydroquinone. *Microdermabrasion* - Offers only **superficial exfoliation** with minimal clinical improvement in melasma pigmentation. - May actually **worsen pigmentation** through mechanical irritation and is not recommended in evidence-based treatment guidelines.

Practice by Chapter

Skin Biopsy Techniques

Practice Questions

Cryotherapy

Practice Questions

Electrosurgery

Practice Questions

Curettage and Electrodessication

Practice Questions

Excisional Surgery

Practice Questions

Mohs Micrographic Surgery

Practice Questions

Chemical Peels

Practice Questions

Dermabrasion and Microdermabrasion

Practice Questions

Laser Therapy Basics

Practice Questions

Injectable Fillers and Botulinum Toxin

Practice Questions

Photodynamic Therapy

Practice Questions

Wound Care and Dressings

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free