Agents for Pigmentary Disorders — MCQs
A 19-year-old woman presents to the dermatology clinic for a follow-up of worsening acne. She has previously tried topical tretinoin as well as topical and oral antibiotics with no improvement. She recently moved to the area for college and says the acne has caused significant emotional distress when it comes to making new friends. She has no significant past medical or surgical history. Family and social history are also noncontributory. The patient’s blood pressure is 118/77 mm Hg, the pulse is 76/min, the respiratory rate is 17/min, and the temperature is 36.6°C (97.9°F). Physical examination reveals erythematous skin lesions including both open and closed comedones with inflammatory lesions overlying her face, neck, and upper back. The patient asks about oral isotretinoin. Which of the following is the most important step in counseling this patient prior to prescribing oral isotretinoin?
Which of the following are treatment options for acne vulgaris?
A 27-year-old sexually active male develops a vesiculobullous lesion on the glans shortly after taking a tablet of paracetamol for fever. The lesion healed with hyperpigmentation. What is the most likely diagnosis?
PUVA therapy is used in all except:
How does narrowband UVB therapy work in psoriasis?
False about melasma is?
Antipsychotic drug causing retinal pigment disorder is which?
A 35 years old female presented with acne. She was treated for her acne but after the treatment, she developed pigmentation. Which drug is responsible for hyperpigmentation?
In which skin disorder is the appearance of basal cells resembling a row of tombstones observed?
Which of the following antidiabetic drugs (other than insulin) is indicated as adjunct therapy for the management of both type I and type II diabetes mellitus?
Agents for Pigmentary Disorders Indian Medical PG Practice Questions and MCQs
Question 1: A 19-year-old woman presents to the dermatology clinic for a follow-up of worsening acne. She has previously tried topical tretinoin as well as topical and oral antibiotics with no improvement. She recently moved to the area for college and says the acne has caused significant emotional distress when it comes to making new friends. She has no significant past medical or surgical history. Family and social history are also noncontributory. The patient’s blood pressure is 118/77 mm Hg, the pulse is 76/min, the respiratory rate is 17/min, and the temperature is 36.6°C (97.9°F). Physical examination reveals erythematous skin lesions including both open and closed comedones with inflammatory lesions overlying her face, neck, and upper back. The patient asks about oral isotretinoin. Which of the following is the most important step in counseling this patient prior to prescribing oral isotretinoin?
- A. Wear a wide-brimmed hat outdoors
- B. Apply topical retinoids in the evening before bed
- C. Document 2 negative urine or blood pregnancy tests before beginning oral isotretinoin (Correct Answer)
- D. Use non-comedogenic sunscreen daily with SPF of at least 45
- E. Avoid direct sunlight, from 10am to 2pm
Explanation: ***Document 2 negative urine or blood pregnancy tests before beginning oral isotretinoin*** - **Oral isotretinoin** is a potent **teratogen**, meaning it can cause severe congenital disabilities if taken during pregnancy. Therefore, ensuring the patient is not pregnant is a critical safety measure. - Due to its high teratogenic risk, female patients of childbearing potential must be enrolled in the **iPLEDGE program**, which requires two negative pregnancy tests prior to starting isotretinoin and monthly negative pregnancy tests during treatment. *Wear a wide-brimmed hat outdoors* - While sun protection is important during isotretinoin treatment due to increased photosensitivity, wearing a wide-brimmed hat alone is not the *most important* counseling step, especially when considering the significant teratogenic risk. - This is a general recommendation for sun protection but does not address the primary safety concern associated with isotretinoin. *Apply topical retinoids in the evening before bed* - The patient has already tried **topical tretinoin** (a topical retinoid) with no improvement, indicating a need for a different treatment approach. - Combining oral isotretinoin with topical retinoids can increase skin irritation and dryness, and it's generally not recommended to use both simultaneously. *Use non-comedogenic sunscreen daily with SPF of at least 45* - Using **sunscreen** is important with isotretinoin due to **photosensitivity**. However, ensuring the patient is not pregnant is a more critical safety step given the severe risks of birth defects. - Sunscreen use is part of general skin care advice for isotretinoin but secondary to pregnancy prevention. *Avoid direct sunlight, from 10am to 2pm* - Avoiding direct sunlight is a good practice for anyone, and especially for those on isotretinoin due to increased **photosensitivity**. However, this is a lifestyle recommendation and not the most crucial safety prerequisite for starting the medication. - The primary concern before initiating treatment is addressing the **teratogenic** potential of the drug.
Question 2: Which of the following are treatment options for acne vulgaris?
- A. Isotretinoin
- B. All of the options (Correct Answer)
- C. Topical erythromycin
- D. Oral Minocycline
Explanation: ***All of the options*** - All listed options (Isotretinoin, Topical erythromycin, and Oral Minocycline) are well-established and commonly used **treatment options for acne vulgaris**, depending on the severity and type of acne. - The choice of treatment often follows a stepped approach, starting with topical agents for mild to moderate acne and progressing to oral medications like antibiotics or isotretinoin for more severe or resistant cases. *Isotretinoin* - **Isotretinoin** is a powerful oral retinoid primarily used for **severe, recalcitrant nodular acne** that has not responded to other treatments. - It works by reducing sebum production, follicular hyperkeratinization, inflammation, and the growth of *P. acnes*. *Topical erythromycin* - **Topical erythromycin** is an **antibiotic** used to treat mild to moderate inflammatory acne by reducing the growth of *Cutibacterium acnes* (formerly *Propionibacterium acnes*) and decreasing inflammation. - It is often combined with other topical agents like benzoyl peroxide to minimize the development of **antibiotic resistance**. *Oral Minocycline* - **Oral minocycline** is a **tetracycline antibiotic** used for moderate to severe inflammatory acne. - It reduces bacterial populations on the skin and exhibits **anti-inflammatory properties**, making it effective for widespread or deeper lesions.
Question 3: A 27-year-old sexually active male develops a vesiculobullous lesion on the glans shortly after taking a tablet of paracetamol for fever. The lesion healed with hyperpigmentation. What is the most likely diagnosis?
- A. Behcet's syndrome
- B. Herpes genitalis
- C. Fixed drug eruption (Correct Answer)
- D. Pemphigus vulgaris
Explanation: ***Fixed drug eruption*** - A **fixed drug eruption** is highly suggested by the development of a solitary **vesiculobullous lesion** on the glans shortly after taking **paracetamol**, which then heals with **hyperpigmentation**. The recurrence at the same site upon re-exposure to the drug is a hallmark. - The rapid appearance following drug intake and the consistent site of eruption with residual pigmentation are classic features. *Behcet's syndrome* - Behcet's syndrome is a **multisystemic inflammatory disorder** characterized by recurrent **oral** and **genital ulcers**, skin lesions, and ocular inflammation. - While it involves genital ulcers, its recurrent nature, systemic symptoms (like uveitis or neurological manifestations), and lack of a clear drug trigger differentiate it from this presentation. *Herpes genitalis* - Herpes genitalis presents with clusters of small, painful, itching **vesicles** often on an erythematous base, but it is caused by the **herpes simplex virus (HSV)** and is sexually transmitted, not drug-induced. - Lesions from herpes typically recur due to viral reactivation, but not in response to a specific medication, and typically resolve without significant hyperpigmentation unless secondary infection occurs. *Pemphigus vulgaris* - Pemphigus vulgaris is a rare, severe **autoimmune blistering disease** affecting the skin and mucous membranes, characterized by **flaccid bullae** that rupture easily, leading to erosions. - This condition presents with widespread blistering, not a solitary, drug-induced lesion, and typically does not heal with localized hyperpigmentation in this manner.
Question 4: PUVA therapy is used in all except:
- A. Psoriasis
- B. Vitiligo
- C. Mycosis fungoides
- D. Melasma (Correct Answer)
Explanation: ***Melasma*** - **PUVA (Psoralen plus UVA) therapy** is contraindicated in melasma due to its potential to worsen hyperpigmentation and cause paradoxical darkening. - Melasma is best managed with topical agents like **hydroquinone**, **tretinoin**, and chemical peels, along with strict **sun protection**. *Psoriasis* - **PUVA therapy** is a well-established and effective treatment for moderate to severe psoriasis, especially for patients with widespread plaques. - It works by inhibiting DNA synthesis and cell proliferation in rapidly dividing keratinocytes, leading to a reduction in psoriatic lesions. *Vitiligo* - **PUVA therapy** is a common treatment for vitiligo, stimulating melanocyte activity and promoting repigmentation in affected areas. - Psoralen sensitizes melanocytes to UVA light, which then encourages melanin production. *Mycosis fungoides* - In its early stages, **mycosis fungoides**, a cutaneous T-cell lymphoma, can be effectively treated with **PUVA therapy**. - PUVA induces apoptosis of malignant T-cells in the skin, leading to remission of skin lesions.
Question 5: How does narrowband UVB therapy work in psoriasis?
- A. Melanin synthesis
- B. Collagen breakdown
- C. Keratinocyte proliferation
- D. T cell apoptosis (Correct Answer)
Explanation: ***T cell apoptosis*** - Narrowband UVB (NB-UVB) therapy primarily works by inducing **apoptosis (programmed cell death)** of activated **T-lymphocytes** in the psoriatic skin lesions. - By reducing the number of these inflammatory cells, NB-UVB helps to suppress the immune response that drives the **excessive keratinocyte proliferation** in psoriasis. *Melanin synthesis* - While UV radiation does stimulate **melanin synthesis**, leading to tanning, this is a secondary effect and not the primary therapeutic mechanism for psoriasis. - Increased melanin helps protect the skin from UV damage but does not directly treat the underlying pathology of psoriasis. *Collagen breakdown* - UV radiation, especially UVA, can contribute to **collagen breakdown** and photodamage over time, but this is an adverse effect, not a therapeutic mechanism for psoriasis. - Psoriasis treatment aims to normalize skin cell growth and reduce inflammation, not degrade collagen. *Keratinocyte proliferation* - Psoriasis is characterized by **accelerated keratinocyte proliferation**; NB-UVB therapy aims to *reduce* this proliferation, not promote it. - The mechanism by which NB-UVB achieves this reduction is primarily through its effects on immune cells, not by directly enhancing keratinocyte growth.
Question 6: False about melasma is?
- A. More common in male (Correct Answer)
- B. Hydroquinone has role in the treatment
- C. Commonly affects sun-exposed areas
- D. Oral contraceptives can induce it
Explanation: ***More common in male*** - **Melasma** is significantly **more common in females** (90%) than in males (10%), especially among women of childbearing age. - This strong female predominance is linked to **hormonal factors**, such as pregnancy and oral contraceptive use. - **This statement is FALSE**, making it the correct answer to this negation question. *Hydroquinone has role in the treatment* - **Hydroquinone** is a **first-line topical treatment** for melasma, working by inhibiting melanin synthesis. - It helps lighten hyperpigmented patches by reducing the activity of **tyrosinase**, a key enzyme in melanin production. *Commonly affects sun-exposed areas* - **Melasma** typically presents on **sun-exposed areas** of the face, particularly the cheeks, forehead, upper lip, and chin. - **UV exposure** is a major triggering and exacerbating factor, which is why sun protection is crucial in management. *Oral contraceptives can induce it* - **Oral contraceptive pills** are a well-known trigger for **melasma**, due to the hormonal changes they induce (estrogen and progesterone). - The elevated **hormone levels** stimulate melanocytes, leading to increased melanin production and hyperpigmentation.
Question 7: Antipsychotic drug causing retinal pigment disorder is which?
- A. Clozapine
- B. Chlorpromazine
- C. None of the options
- D. Thioridazine (Correct Answer)
Explanation: ***Thioridazine*** - **Thioridazine** is a **first-generation antipsychotic** known to cause **retinal pigmentary changes** (pigmentary retinopathy) at high doses, particularly above 800 mg/day. - This condition can lead to **vision loss** due to the deposition of melanin-like pigment in the retina and progressive retinal degeneration. - This is a dose-related toxic effect and is one of the reasons thioridazine is less commonly used today. *Clozapine* - **Clozapine** is primarily associated with severe side effects like **agranulocytosis** and **myocarditis**. - It is not typically known to cause **retinal pigment disorder** as a common or significant side effect. *Chlorpromazine* - **Chlorpromazine**, another first-generation antipsychotic, is more commonly linked to **corneal and lenticular opacities** (blue-gray discoloration of the eye) than retinal pigment changes. - While it can affect the eye, its primary ocular toxicity differs from the **retinal pigment disorder** caused by thioridazine. *None of the options* - This option is incorrect because **Thioridazine** is a well-established cause of **retinal pigment disorder**. - There is a specific antipsychotic drug listed that causes this condition.
Question 8: A 35 years old female presented with acne. She was treated for her acne but after the treatment, she developed pigmentation. Which drug is responsible for hyperpigmentation?
- A. Minocycline (Correct Answer)
- B. Doxycycline
- C. Tetracycline
- D. Erythromycin
Explanation: ***Minocycline*** - **Minocycline** is known to cause different types of hyperpigmentation, including blue-grey discoloration of the skin, scars, mucosa, eyes, and teeth, especially with long-term use. - This pigmentation can be due to the accumulation of **iron oxide** and **minocycline degradation products** in tissues. *Doxycycline (a tetracycline antibiotic)* - While doxycycline is a tetracycline, it is **less commonly associated with significant hyperpigmentation** compared to minocycline. - It can cause photosensitivity, which might lead to hyperpigmentation in sun-exposed areas, but direct drug-induced blue-grey discoloration is rare. *Tetracycline (a tetracycline antibiotic)* - **Tetracycline** can cause tooth discoloration, especially in children, and photosensitivity, but direct drug-induced skin hyperpigmentation as described is **less common** than with minocycline. - Other side effects like gastrointestinal upset are more prominent. *Erythromycin (a macrolide antibiotic)* - **Erythromycin** is a macrolide antibiotic and is **not typically associated with significant skin hyperpigmentation** as a side effect. - Common side effects include gastrointestinal disturbances like nausea, vomiting, and diarrhea.
Question 9: In which skin disorder is the appearance of basal cells resembling a row of tombstones observed?
- A. Pemphigus vulgaris (Correct Answer)
- B. Pemphigus foliaceus
- C. Erythema multiforme
- D. Bullous pemphigoid
Explanation: ***Pemphigus vulgaris*** - This autoimmune blistering disease is characterized by **acantholysis** (loss of cell-to-cell adhesion) in the **suprabasal layer** of the epidermis [2]. - The intact basal keratinocytes remain attached to the basement membrane, forming a characteristic "row of **tombstones**" appearance on histology [1]. *Pemphigus foliaceus* - This condition involves acantholysis in the more **superficial granular layer** of the epidermis, above the basal layer [2]. - This leads to subcorneal blistering and **crusted lesions**, but not the tombstone appearance [2]. *Erythema multiforme* - This is a **(type IV hypersensitivity reaction)** characterized by **target lesions** and **vacuolar degeneration** of the basal cell layer. - While it affects the basal layer, it does not involve acantholysis or the "tombstone" pattern. *Bullous pemphigoid* - This is a **subepidermal blistering disease** where autoantibodies target components of the **hemidesmosomes** at the dermoepidermal junction [2]. - The entire epidermis separates from the dermis, resulting in a **tense blister** and no acantholysis or tombstone appearance [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Disorders Involving Inflammatory And Haemopoietic Cells, pp. 645-646. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, pp. 1170-1172.
Question 10: Which of the following antidiabetic drugs (other than insulin) is indicated as adjunct therapy for the management of both type I and type II diabetes mellitus?
- A. Sulphonylureas
- B. Metformin
- C. Acarbose
- D. Pramlintide (Correct Answer)
Explanation: Pramlintide - Pramlintide is an amylin analog indicated as an adjunct therapy to insulin for both type 1 and type 2 diabetes, helping to regulate post-prandial glucose. - It slows gastric emptying, suppresses postprandial glucagon secretion, and promotes satiety, leading to reduced insulin requirements and improved glycemic control. Sulphonylureas - Sulphonylureas primarily stimulate insulin secretion from pancreatic beta cells, making them effective only in Type 2 diabetes where some beta-cell function is preserved [2]. - They are not indicated for Type 1 diabetes because these patients have absolute insulin deficiency due to beta cell destruction. Metformin - Metformin is a biguanide that primarily reduces hepatic glucose production and improves insulin sensitivity in peripheral tissues. - It is a first-line treatment for Type 2 diabetes but is generally not used for Type 1 diabetes as it does not address the fundamental lack of insulin. Acarbose - Acarbose is an alpha-glucosidase inhibitor that works by delaying carbohydrate absorption from the gastrointestinal tract, thus reducing postprandial glucose spikes [1]. - While it can be used in Type 2 diabetes to manage postprandial hyperglycemia, it is not typically indicated as an adjunct for Type 1 diabetes alongside insulin [3].
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