Management of Hyperpigmentation — 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 one of these should not be used in severe widespread psoriasis?
What is the optimal wavelength of light emitted by a Wood's lamp for dermatological examinations?
Which drug is generally contraindicated in the management of traumatic hyphema in a patient with sickle cell disease?
Microabrasion using modified Croll technique utilizes:
A 17 year old girl had been taking a drug for the treatment of acne for the last 2 years, which has led to pigmentation. Which drug could it be?
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?
Dermatological manifestation of which of the following diseases?
Which of the following is not true about hydroquinone?
What is the most common association with Acanthosis nigricans?
Management of Hyperpigmentation 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 one of these should not be used in severe widespread psoriasis?
- A. Methotrexate
- B. Oral retinoids
- C. Cyclosporin
- D. Oral glucocorticoids (Correct Answer)
Explanation: ***Oral glucocorticoids*** - While they may provide temporary relief, **oral glucocorticoids** can exacerbate psoriasis upon withdrawal, leading to a severe flare-up or **pustular psoriasis**. - Their long-term use is associated with numerous side effects, making them unsuitable for widespread, chronic conditions like severe psoriasis. *Methotrexate* - **Methotrexate** is a systemic agent commonly used for severe psoriasis due to its immune-modulating and anti-proliferative effects. - It is effective in reducing inflammation and slowing down epidermal cell turnover. *Oral retinoids* - **Oral retinoids** like acitretin are effective systemic treatments for severe widespread psoriasis, especially **pustular** and **erythrodermic** forms. - They work by normalizing keratinocyte proliferation and differentiation. *Cyclosporin* - **Cyclosporin** is a potent immunosuppressant widely used for severe psoriasis, particularly when rapid disease control is needed. - It works by inhibiting T-cell activation and is highly effective in clearing psoriatic lesions.
Question 3: What is the optimal wavelength of light emitted by a Wood's lamp for dermatological examinations?
- A. 365 nm (Correct Answer)
- B. 400 nm
- C. 320 nm
- D. 200 nm
Explanation: **365 nm** - A Wood's lamp primarily emits **long-wave UVA light** in the 320 to 400 nm range, with an optimal peak around **365 nm**. - This specific wavelength is ideal for inducing **fluorescence** in various dermatological conditions, making them visible. *400 nm* - While within the UVA range, **400 nm** is at the higher end and may not provide the optimal fluorescence yield for all diagnostic purposes compared to 365 nm. - Light at 400 nm is closer to the visible light spectrum and might offer less distinction for subtle fluorescence. *320 nm* - **320 nm** is at the lower end of the UVA spectrum, bordering on UVB. - While still capable of inducing some fluorescence, it is generally less effective than 365 nm for the conditions typically examined with a Wood's lamp. *200 nm* - **200 nm** falls into the **UVC range** (100-280 nm), which is harmful and not used for diagnostic purposes in a Wood's lamp. - This wavelength is absorbed by the atmosphere and epidermis and can cause significant **DNA damage**, making it unsafe for routine dermatological examination.
Question 4: Which drug is generally contraindicated in the management of traumatic hyphema in a patient with sickle cell disease?
- A. Timolol
- B. Steroids
- C. Acetazolamide (Correct Answer)
- D. Atropine
Explanation: ***Acetazolamide*** - **Acetazolamide** is a **carbonic anhydrase inhibitor** that is **generally contraindicated** in patients with **sickle cell disease or trait**. - It causes **systemic acidosis** by increasing renal bicarbonate excretion, which lowers blood pH. - **Acidosis promotes sickling** of red blood cells, which can lead to **vaso-occlusion**, increased blood viscosity, and potential complications including **anterior chamber obstruction** and **secondary glaucoma**. - Despite its usefulness in lowering intraocular pressure in other settings, this risk makes it contraindicated in sickle cell patients with hyphema. *Timolol* - **Timolol** is a **beta-blocker** that reduces aqueous humor production and is generally **safe and effective** for reducing **intraocular pressure** in traumatic hyphema. - It does not cause systemic acidosis or affect red blood cell sickling. - Commonly used in hyphema management regardless of sickle cell status. *Steroids* - **Topical or systemic steroids** are often used to reduce **inflammation** and anterior chamber reaction in traumatic hyphema. - They help prevent **secondary hemorrhage** and reduce complications. - They do not contribute to red blood cell sickling or systemic acidosis and are safe in sickle cell disease. *Atropine* - **Atropine** is a **cycloplegic agent** used to paralyze the ciliary body and dilate the pupil, which helps **relieve pain** and prevent **posterior synechiae** in hyphema. - It has no adverse effects related to **sickle cell disease** or red blood cell sickling. - Routinely used in hyphema management.
Question 5: Microabrasion using modified Croll technique utilizes:
- A. 5% HF
- B. 37% Phosphoric Acid
- C. 10% HCl
- D. 18% Citric acid (Correct Answer)
Explanation: ***18% Citric acid*** - The modified Croll technique for **microabrasion** specifically utilizes an 18% solution of **citric acid**. - This technique is effective for removing superficial enamel discolorations and opacities by gently abrading the affected surface. *5% HF* - **Hydrofluoric acid (HF)** is a highly corrosive acid primarily used by **dental technicians** for etching ceramic restorations, not for in-office microabrasion on natural teeth. - Due to its extreme toxicity and potential for severe tissue damage, HF is generally not used intraorally for enamel procedures. *37% Phosphoric Acid* - **37% phosphoric acid** is routinely used in dentistry as an **etchant** to prepare enamel and dentin surfaces for bonding procedures, creating a microporous surface for resin penetration. - Its mechanism is to demineralize the tooth surface to enhance adhesion, not to mechanically abrade or remove superficial stains in the same manner as microabrasion. *10% HCl* - While hydrochloric acid (HCl) was historically used in earlier microabrasion techniques, the **modified Croll technique** specifically moved to **citric acid** due to its gentler nature and reduced potential for adverse effects on tooth structure compared to stronger acids. - Stronger concentrations of HCl can be more aggressive and carry a higher risk of excessive enamel removal or chemical burns if not carefully controlled.
Question 6: A 17 year old girl had been taking a drug for the treatment of acne for the last 2 years, which has led to pigmentation. Which drug could it be?
- A. Doxycycline
- B. Minocycline (Correct Answer)
- C. Clindamycin
- D. Azithromycin
Explanation: ***Minocycline*** - **Minocycline** is a **tetracycline** antibiotic commonly used for acne and is notorious for causing various forms of **pigmentation**, including blue-gray discoloration of the skin, scars, and teeth, especially with long-term use. - This pigmentation is due to the formation of **insoluble chelates** of minocycline with iron and melanin within tissues. *Doxycycline* - While also a **tetracycline**, **doxycycline** is less commonly associated with significant **skin pigmentation** compared to minocycline at standard acne treatment doses. - Its side effect profile for pigmentation usually involves **photosensitivity** or **tooth discoloration** in children, not generally diffuse skin discoloration in adolescents. *Clindamycin* - **Clindamycin** is a **lincosamide antibiotic** primarily used topically or orally for acne, but it does not cause **pigmentation** as a known side effect. - Its main systemic side effect concern is **Clostridioides difficile-associated diarrhea (CDAD)**. *Azithromycin* - **Azithromycin** is a **macrolide antibiotic** and is not typically associated with **skin pigmentation** as a side effect. - It is sometimes used for acne, but its side effects are primarily **gastrointestinal** (nausea, vomiting, diarrhea).
Question 7: 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 8: Dermatological manifestation of which of the following diseases?
- A. Photo dermatitis
- B. Pellagra (Correct Answer)
- C. Acrodermatitis enteropathica
- D. Vitamin B deficiency
Explanation: ***Pellagra*** - The image shows a classic "butterfly" rash on the face, specifically a photosensitive dermatitis, which is a hallmark of **pellagra**. - Pellagra is caused by a deficiency of **niacin (vitamin B3)**, characterized by the "3 D's": **dermatitis**, **diarrhea**, and **dementia**. *Photo dermatitis* - While pellagra often presents with photosensitive dermatitis, "photo dermatitis" is a general term for **skin inflammation caused by light exposure** and not a specific disease itself. - It could be caused by various factors, including medication, immune reactions, or other underlying conditions, but the pattern seen here is highly suggestive of pellagra. *Acrodermatitis enteropathica* - This condition is a **hereditary zinc deficiency** that typically presents with a periorificial and acral dermatitis. - The skin lesions are typically **vesicular-pustular or eczematous** and do not usually have the distinct butterfly pattern of photosensitive dermatitis seen in the image. *Vitamin B deficiency* - While pellagra is a vitamin B **(niacin, B3)** deficiency, this option is too broad. - Other vitamin B deficiencies, such as **riboflavin (B2)** or **pyridoxine (B6)** deficiency, have different dermatological manifestations like angular cheilitis, glossitis, or seborrheic dermatitis, but not the characteristic facial rash seen here.
Question 9: Which of the following is not true about hydroquinone?
- A. Response is incomplete and pigmentation may recur
- B. It inhibits tyrosinase
- C. It requires prescription strength concentrations above 2%
- D. It should not be used for melasma or chloasma of pregnancy (Correct Answer)
Explanation: ***It should not be used for melasma or chloasma of pregnancy*** - This statement is **NOT TRUE** - hydroquinone is actually a **first-line treatment for melasma** including chloasma (melasma of pregnancy) - Hydroquinone 2-4% is one of the **most effective topical agents** for treating melasma and is widely recommended in dermatological guidelines - While hydroquinone use during **active pregnancy** is approached with caution (FDA Category C), it is definitely indicated for treating melasma/chloasma **after pregnancy** and for general melasma in non-pregnant patients - The condition (melasma/chloasma) is appropriately treated with hydroquinone; only the **timing during pregnancy** requires consideration *Response is incomplete and pigmentation may recur* - This is a **TRUE statement** about hydroquinone therapy - Treatment response is often **incomplete** with partial lightening of hyperpigmentation - **Recurrence is common** after discontinuation, especially with continued sun exposure or hormonal triggers - Maintenance therapy is often needed to sustain results *It inhibits tyrosinase* - This is a **TRUE statement** - hydroquinone's primary mechanism of action - Acts as a **competitive inhibitor of tyrosinase**, the rate-limiting enzyme in melanin synthesis - This inhibition reduces melanin production in melanocytes, leading to depigmentation *It requires prescription strength concentrations above 2%* - This is a **TRUE statement** in most countries including India and the USA - Hydroquinone concentrations **≤2%** are available over-the-counter (OTC) - Concentrations **>2% (typically 3-4%)** require a prescription - Higher concentrations provide greater efficacy but also increased risk of side effects like ochronosis
Question 10: What is the most common association with Acanthosis nigricans?
- A. Hypertension
- B. Diabetes Mellitus
- C. Obesity (Correct Answer)
- D. Hypothyroidism
Explanation: **Explanation:** **Acanthosis Nigricans (AN)** is a common dermatological condition characterized by hyperpigmented, velvety plaques, typically found in intertriginous areas like the axilla and neck. **Why Obesity is the Correct Answer:** Obesity is the **most common** association and cause of Acanthosis Nigricans (Pseudo-acanthosis nigricans). The underlying mechanism is **Insulin Resistance**. In obese individuals, high levels of circulating insulin bind to **Insulin-like Growth Factor-1 (IGF-1) receptors** on keratinocytes and fibroblasts. This stimulates excessive proliferation of these cells, leading to the characteristic epidermal thickening and hyperpigmentation. **Analysis of Incorrect Options:** * **Diabetes Mellitus (B):** While AN is a strong cutaneous marker for Type 2 Diabetes, it usually precedes the clinical onset of diabetes. Obesity remains the primary driver and more frequent association. * **Hypertension (A) & Hypothyroidism (D):** These are often part of the "Metabolic Syndrome" or associated endocrinopathies (like PCOS), but they are not the primary or most common cause of the skin changes seen in AN. **High-Yield Clinical Pearls for NEET-PG:** * **Malignant Acanthosis Nigricans:** If AN appears suddenly, is very extensive, or involves the palms (**Tripe Palms**) and oral mucosa, it is highly suggestive of internal malignancy, most commonly **Gastric Adenocarcinoma**. * **Histopathology:** Shows hyperkeratosis and papillomatosis. Note that "acanthosis" (thickening of the stratum spinosum) is actually minimal despite the name. * **Common Sites:** Neck (most common), axilla, groins, and knuckles. * **Drug-induced AN:** Can be caused by Nicotinic acid, systemic corticosteroids, and OCPs.
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