Drugs Used in Skin Disorders Practice Questions

Q: Which of the following topical steroids is the most potent?

Halobetasol propionate. ***Correct: Halobetasol propionate*** - **Halobetasol propionate** is a **Class I (super-high potency) topical corticosteroid**, indicating it is among the strongest available. - Its high potency is used for severe dermatoses like psoriasis and lichen planus, but requires careful monitoring due to potential side effects like **skin atrophy**, telangiectasia, and hypothalamic-pituitary-adrenal (HPA) axis suppression. - Should be used for short durations and limited to small body surface areas. *Incorrect: Hydrocortisone* - **Hydrocortisone** is a **Class VII (lowest potency)** topical steroid, primarily used for mild inflammatory conditions like mild eczema or diaper dermatitis. - It is significantly less potent than halobetasol propionate and is often available in over-the-counter preparations. - Safest option for use on face, intertriginous areas, and in children. *Incorrect: Fluticasone* - **Fluticasone propionate** is typically a **medium-potency (Class IV-V)** topical corticosteroid, depending on the formulation and vehicle. - It is commonly used for moderate inflammatory skin conditions like atopic dermatitis, but is not as strong as Class I agents. *Incorrect: Triamcinolone acetonide* - **Triamcinolone acetonide** is available in various strengths, typically falling into **medium-to-high potency categories (Class III-IV)**, depending on the vehicle and concentration. - While effective for many conditions like psoriasis and eczema, it is not considered the most potent topical steroid category, which is occupied by agents like halobetasol propionate and clobetasol propionate.

Q: Most common side effect of retinoids is

Mucocutaneous dryness. ***Mucocutaneous dryness*** - This is the **most common side effect** of retinoids, particularly oral isotretinoin, occurring in nearly all patients - Manifests as **cheilitis** (dry, cracked lips), **xerosis** (dry skin), **dry nasal mucosa**, and **conjunctival dryness** - Direct result of decreased sebaceous gland activity and altered epithelial differentiation - Managed with **emollients and lip balm** *Headache* - Can occur with retinoid use, but less common than mucocutaneous effects - **Severe headaches** with visual changes may indicate **pseudotumor cerebri** (benign intracranial hypertension), a rare but serious complication requiring immediate discontinuation *Diarrhoea* - **Gastrointestinal side effects** are uncommon with systemic retinoids - Not a characteristic adverse effect of this drug class *Photosensitivity* - While retinoids can increase susceptibility to **sunburn**, this is not the most common side effect - Patients should be advised to use **sunscreen** and avoid excessive sun exposure - Less universal than mucocutaneous dryness

Q: All of the following are topical steroids EXCEPT ?

Prednisolone. ***Prednisolone*** - **Prednisolone** is an **oral/systemic corticosteroid** primarily used for systemic therapy, not as a topical dermatological preparation. - While prednisolone eye drops and ear drops exist, it is NOT a standard topical corticosteroid for skin disorders. - Its high systemic absorption potential makes it unsuitable for dermatological topical applications. *Fluticasone propionate* - **Fluticasone propionate** is a **highly potent synthetic topical corticosteroid** commonly used in dermatology. - Available as creams and ointments for inflammatory skin conditions like eczema, psoriasis, and atopic dermatitis. - Also formulated as nasal spray for allergic rhinitis. *Betamethasone valerate* - **Betamethasone valerate** is a **potent topical corticosteroid** widely used in dermatology. - Available in various formulations (cream, ointment, lotion) for treating inflammatory skin conditions. - Classified as a mid-to-high potency topical steroid, effective for conditions like eczema, psoriasis, and contact dermatitis. *Hydrocortisone valerate* - **Hydrocortisone valerate** is a **moderate-potency topical corticosteroid** derived from hydrocortisone. - Frequently used in dermatological preparations to treat inflammatory skin conditions like dermatitis and eczema. - Safer for prolonged use and application on sensitive areas compared to more potent steroids.

Q: Which of the following drugs are used topically for dermatophytes?

All of the options. ***All of the options*** - **Terbinafine**, **Ciclopirox olamine**, and **Econazole** are all commonly used as topical antifungal agents for the treatment of dermatophyte infections. - These drugs target different aspects of fungal cell metabolism or structure to inhibit growth or kill the fungus. *Terbinafine* - It is an **allylamine antifungal** that inhibits **squalene epoxidase**, an enzyme involved in fungal ergosterol synthesis. - While effective topically, terbinafine can also be used orally for more extensive or recalcitrant infections, but the question specifically asks for topical use. *Cyclopirox olamine* - This is a **hydroxypyridone antifungal** that acts by chelating polyvalent metal cations, inhibiting essential enzymes in fungal cells. - It is often used for topical treatment of dermatophyte infections, including **tinea pedis** and **tinea corporis**, and is also used for onychomycosis. *Econazole* - It is an **imidazole antifungal** that inhibits the fungal cytochrome P450 enzyme 14α-demethylase, which is crucial for **ergosterol biosynthesis**. - Commonly available as a cream or solution, econazole is effective against a broad spectrum of fungi, including dermatophytes, and is used for various superficial fungal infections.

Q: Contraindicated in Androgenic Alopecia –

Testosterone. ***Testosterone*** - Androgenic alopecia, or **male-pattern baldness**, is driven by **androgens**, particularly **dihydrotestosterone (DHT)**, which is derived from testosterone. - Administering exogenous **testosterone** would exacerbate hair loss in individuals with androgenic alopecia by increasing the substrate available for conversion to DHT. *Minoxidil* - **Minoxidil** is a vasodilator that is commonly used topically to treat androgenic alopecia. - It works by **prolonging the anagen phase** of hair growth and increasing follicular size, making it a treatment option, not a contraindication. *Cyproterone* - **Cyproterone** is an **anti-androgen** that blocks androgen receptors and inhibits androgen synthesis. - It is used in some cases of severe androgenic alopecia in women, making it a treatment, not a contraindication. *Finasteride* - **Finasteride** is a **5-alpha-reductase inhibitor** that blocks the conversion of testosterone to dihydrotestosterone (DHT). - By reducing DHT levels, it slows or reverses hair loss in androgenic alopecia, making it a common treatment and not a contraindication.

Q: FTU is a measure of:

Amount of topical drug to be applied. ***Amount of topical drug to be applied*** - A **finger-tip unit (FTU)** is a standardized measure representing the amount of topical medication needed to cover a specific body area, typically about **0.5 grams**. - It ensures appropriate dosing, as one FTU is generally sufficient to treat an area equivalent to the size of an adult hand (palm and fingers). *Mucosal involvement in pemphigus* - **FTU** is a measure for **topical drug application**, not for assessing the extent of mucosal lesions in autoimmune bullous diseases like pemphigus. - The severity of pemphigus, including mucosal involvement, is assessed by clinical examination and specific scoring systems. *Area involved in severe drug reactions* - The **FTU** is not used to quantify the body surface area affected in severe drug reactions. - Conditions like **Stevens-Johnson Syndrome (SJS)** or **Toxic Epidermal Necrolysis (TEN)** use specific scoring systems and percentages of body surface area for assessment. *Concentration of drug in topical preparations* - **FTU** refers to the **volume or weight** of a topical product, not the concentration of the active drug within the preparation. - The drug concentration is typically expressed as a percentage or mg/g and is listed on the product packaging.

Q: All these drugs are known to exacerbate psoriasis, except:

Ciclosporin. ***Ciclosporin*** - **Ciclosporin** is an immunosuppressant often used to **treat severe psoriasis**, not exacerbate it. - It works by inhibiting the activation of T-cells, which are central to the pathogenesis of psoriasis. *Beta blocker* - **Beta-blockers**, particularly non-selective ones like **propranolol**, can worsen existing psoriasis or induce new lesions. - The mechanism is thought to involve effects on beta-adrenergic receptors in the skin, leading to inflammation. *Hydroxychloroquine* - **Hydroxychloroquine**, an antimalarial and immunosuppressant, can trigger or exacerbate psoriasis, especially **pustular psoriasis**. - It likely affects keratinocyte proliferation and immune responses in the skin. *Lithium* - **Lithium** is a mood stabilizer that is known to exacerbate or trigger various forms of psoriasis, including **plaque psoriasis** and **pustular psoriasis**. - The mechanism is believed to involve alterations in cyclic AMP metabolism and arachidonic acid pathways within keratinocytes.

Q: Dapsone is NOT used in:

Alopecia areata. ***Alopecia areata*** - **Dapsone** is an **antibiotic** with anti-inflammatory and immunomodulatory properties and is not indicated for the treatment of **alopecia areata**. - Treatment for **alopecia areata** typically involves **corticosteroids** (topical, intralesional, or systemic) or other immunosuppressants. *Dermatitis herpetiformis* - **Dapsone** is the **first-line treatment** for **dermatitis herpetiformis** due to its rapid antipruritic effect, often providing relief within 24-48 hours. - It works by reducing the inflammation and formation of the characteristic **subepidermal blisters** seen in this condition. *Pneumocystis jirovecii pneumonia prophylaxis* - **Dapsone** is an effective **alternative agent** for prophylaxis against **Pneumocystis jirovecii pneumonia (PCP)**, especially in patients who cannot tolerate trimethoprim-sulfamethoxazole. - It is often used in combination with **pyrimethamine** for toxoplasmosis prophylaxis in HIV-infected patients. *Leprosy* - **Dapsone** is a crucial component of **multidrug therapy (MDT)** for both paucibacillary and multibacillary forms of **leprosy**. - It acts as a **bacteriostatic agent** against Mycobacterium leprae and has been a cornerstone of leprosy treatment for decades.

Q: Imiquimod is administered by which route?

Topical. ***Topical*** - **Imiquimod** is a topical immune response modifier that is applied directly to the skin as a cream (typically 5% concentration). - It is commonly used for the treatment of **external genital and perianal warts**, superficial basal cell carcinoma, and actinic keratosis. - Works by stimulating local immune response through **toll-like receptor 7 (TLR7) activation**. *Inhalation* - **Imiquimod** is not formulated for inhalation and is not effective when administered via the respiratory tract. - It is specifically designed as a dermatological preparation for **direct skin application** only. *Intranasal* - **Imiquimod** is not designed for intranasal administration and would not achieve therapeutic concentrations at target sites this way. - Intranasal application could lead to **mucosal irritation** and lack of efficacy for its primary dermatological indications. *Oral* - **Imiquimod** is not available in oral formulation and would not be effective systemically. - Its mechanism requires **local application** to activate skin-resident immune cells at the site of pathology.

Q: Scabies oral treatment of choice:

Ivermectin. ***Ivermectin*** - **Ivermectin** is the **oral treatment of choice** for scabies, especially in cases of crusted (Norwegian) scabies, immunocompromised patients, or when topical treatments fail. - It works by disrupting the **neurotransmitter system** of parasites, leading to paralysis and death of the scabies mites. *Benzyl Benzoate* - **Benzyl benzoate** is a **topical scabicide** and acaricide, used as a lotion or emulsion. - It is not available as an oral formulation and is typically reserved for cases where other topical agents are ineffective or contraindicated. *Lindane* - **Lindane** (gamma-hexachlorocyclohexane) is a topical scabicide but is **not recommended as a first-line treatment** due to potential **neurotoxicity** (seizures) especially in infants, children, and individuals with extensive skin excoriations. - It is used topically and has significant systemic absorption, making its use limited. *Permethrin* - **Permethrin** cream is considered the **first-line topical treatment** for scabies, showing high efficacy and a good safety profile. - It is not an oral medication; it is applied topically to the skin to kill mites.

Question 1

Which of the following topical steroids is the most potent?

Accepted Answer

Halobetasol propionate

Answer

Hydrocortisone

Answer

Fluticasone

Answer

Triamcinolone acetonide

Question 2

Most common side effect of retinoids is

Accepted Answer

Mucocutaneous dryness

Answer

Headache

Answer

Diarrhoea

Answer

Photosensitivity

Question 3

All of the following are topical steroids EXCEPT ?

Accepted Answer

Prednisolone

Answer

Fluticasone propionate

Answer

Betamethasone valerate

Answer

Hydrocortisone valerate

Question 4

Which of the following drugs are used topically for dermatophytes?

Accepted Answer

All of the options

Answer

Terbinafine

Answer

Cyclopirox olamine

Answer

Econazole

Question 5

Contraindicated in Androgenic Alopecia –

Accepted Answer

Testosterone

Answer

Minoxidil

Answer

Cyproterone

Answer

Finasteride

Question 6

FTU is a measure of:

Accepted Answer

Amount of topical drug to be applied

Answer

Mucosal involvement in pemphigus

Answer

Area involved in severe drug reactions

Answer

Concentration of drug in topical preparations

Question 7

All these drugs are known to exacerbate psoriasis, except:

Accepted Answer

Ciclosporin

Answer

Beta blocker

Answer

Hydroxychloroquine

Answer

Lithium

Question 8

Dapsone is NOT used in:

Accepted Answer

Alopecia areata

Answer

Dermatitis herpetiformis

Answer

Pneumocystis jirovecii pneumonia prophylaxis

Answer

Leprosy

Question 9

Imiquimod is administered by which route?

Accepted Answer

Topical

Answer

Inhalation

Answer

Intranasal

Answer

Oral

Question 10

Scabies oral treatment of choice:

Accepted Answer

Ivermectin

Answer

Benzyl Benzoate

Answer

Lindane

Answer

Permethrin

Drugs Used in Skin Disorders — MCQs

Drugs Used in Skin Disorders — MCQs

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