Adverse Cutaneous Drug Reactions Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Adverse Cutaneous Drug Reactions. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Adverse Cutaneous Drug Reactions Indian Medical PG Question 1: 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
Adverse Cutaneous Drug Reactions 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.
Adverse Cutaneous Drug Reactions Indian Medical PG Question 2: A patient with psoriasis was started on systemic steroids. After stopping the treatment, the patient developed universally red scaly skin with plaques losing their margins all over his body. The most likely cause is –
- A. Pustular psoriasis
- B. Erythrodermic psoriasis (Correct Answer)
- C. Drug induced reaction
- D. Bacterial infection
Adverse Cutaneous Drug Reactions Explanation: ***Erythrodermic Psoriasis***
- This condition is characterized by **widespread erythema** and scaling affecting over 90% of the body surface, often with a loss of distinct plaque margins.
- The sudden withdrawal of **systemic corticosteroids** in patients with psoriasis is a well-known trigger for erythrodermic psoriasis.
*Pustular psoriasis*
- This form presents with widespread or localized pustules, often on an erythrematous base, and may be accompanied by fever and systemic symptoms.
- While it can be severe, the primary described feature here is **universal redness and scaling with plaque confluence**, not predominant pustule formation.
*Drug induced reaction*
- While drugs can induce or exacerbate psoriasis, the specific trigger described (withdrawal of systemic steroids) points more directly to a rebound phenomenon of the underlying psoriasis.
- A drug-induced reaction would typically be an *initial* eruption or a different morphology, not a flare of pre-existing psoriasis due to *cessation* of treatment.
*Bacterial infection*
- A bacterial infection might cause redness, scaling, and inflammation, but it would typically be accompanied by signs of infection like fever, purulence, or pus.
- The described condition is a direct rebound phenomenon after steroid withdrawal, not primarily an infective process.
Adverse Cutaneous Drug Reactions Indian Medical PG Question 3: A patient with acute history of blistering and denudation involving >30% BSA along with erosions of the lips with hemorrhagic crusting and other mucosa for few days. What is the most common triggering factor?
- A. Drug induced (Correct Answer)
- B. Viral infection
- C. Idiopathic
- D. Bacterial infection
Adverse Cutaneous Drug Reactions Explanation: ***Drug induced***
- **Toxic epidermal necrolysis (TEN)**, characterized by blistering and denudation of >30% body surface area and mucosal involvement, is most commonly triggered by **drugs**, such as sulfonamides, antiepileptics, allopurinol, and NSAIDs.
- The rapid onset and severe presentation are highly suggestive of an adverse drug reaction.
*Viral infection*
- While viruses can trigger some mucocutaneous reactions, severe widespread necrosis and denudation like in TEN are not typically **direct viral effects**.
- **Herpes simplex virus (HSV)** can cause erythema multiforme, which is less severe and extensive than TEN.
*Idiopathic*
- While some cases of severe cutaneous adverse reactions can be idiopathic, the vast majority of **TEN cases have an identifiable trigger**, with drugs being the leading cause.
- Attributing it to an unknown cause would be less precise given the common association with medications.
*Bacterial infection*
- Bacterial infections, such as **Staphylococcal scalded skin syndrome (SSSS)**, can cause blistering and desquamation, but it primarily affects children and involves a superficial epidermal split, rather than the full-thickness necrosis seen in TEN.
- SSSS typically spares the **mucous membranes**, unlike the prominent mucosal involvement described in the patient.
Adverse Cutaneous Drug Reactions Indian Medical PG Question 4: The patient came with a history of bullae involving more than 30% of body surface area, along with erosions of the lips and other mucosae for the past 7 days. What is the most probable underlying etiology?
- A. Drugs (Correct Answer)
- B. Malignancy
- C. Bacterial infection
- D. Viral infection
Adverse Cutaneous Drug Reactions Explanation: ***Drugs***
- This presentation is **highly characteristic of Toxic Epidermal Necrolysis (TEN)**, which is typically drug-induced. TEN is defined by **>30% body surface area (BSA) involvement** with epidermal detachment, distinguishing it from Stevens-Johnson Syndrome (SJS, <10% BSA) and SJS-TEN overlap (10-30% BSA).
- The patient's presentation of bullae involving over 30% BSA with **extensive mucosal involvement** (lips and other mucosae) and **acute onset over 7 days** is pathognomonic for drug-induced TEN.
- Common culprit drugs include **sulfonamides, anticonvulsants (carbamazepine, phenytoin), NSAIDs, allopurinol**, and **antibiotics**, which trigger a severe cell-mediated cytotoxic reaction leading to widespread keratinocyte apoptosis and epidermal detachment.
*Bacterial infection*
- While bacterial infections can cause skin blistering (e.g., **bullous impetigo** caused by *Staphylococcus aureus* or **Staphylococcal Scalded Skin Syndrome**), they rarely lead to the widespread severe epidermal detachment of over 30% BSA with extensive mucosal involvement seen in this case.
- The rapid progression to generalized large bullae and erosions suggests a systemic immune-mediated reaction rather than a localized bacterial process.
*Malignancy*
- Malignancy can be associated with **paraneoplastic pemphigus**, which causes severe mucocutaneous blistering, but its onset is typically more gradual and chronic rather than acute.
- The rapid progression over 7 days to over 30% BSA involvement is less characteristic of a paraneoplastic process and more typical of an acute drug reaction like TEN.
*Viral infection*
- Viral infections like **herpes simplex virus (HSV)** or **varicella-zoster virus (VZV)** can cause vesicular lesions, but they typically present with vesicles in specific distributions and not generalized bullae covering more than 30% BSA with extensive mucosal erosions.
- While **Mycoplasma pneumoniae** infection can trigger SJS/TEN (particularly in children), and certain viral infections can serve as triggers, the **abrupt onset** and **severity** described point more strongly towards a direct drug etiology as the most probable cause.
Adverse Cutaneous Drug Reactions Indian Medical PG Question 5: Which of the following is classified as a Type E adverse reaction?
- A. Toxicity
- B. Augmented effect
- C. Teratogenesis
- D. Rebound effect due to drug withdrawal (Correct Answer)
Adverse Cutaneous Drug Reactions Explanation: ***Rebound effect due to drug withdrawal***
- Type E adverse reactions are related to **end-of-treatment effects**, specifically withdrawal phenomena.
- The **rebound effect** after drug cessation, such as worsened angina after stopping beta-blockers, is a classic example of a Type E reaction.
*Toxicity*
- This is a general term for adverse effects from excessive drug doses and is **not a specific type** in the ABCDEF classification.
- Dose-dependent toxic effects typically align with **Type A** (augmented) reactions, which are predictable and related to the drug's pharmacology.
*Augmented effect*
- An **augmented effect** is classified as a Type A adverse drug reaction, meaning it is **dose-dependent**, predictable from the drug's known pharmacology, and common.
- Examples include bleeding with anticoagulants or hypotension with antihypertensives.
*Teratogenesis*
- **Teratogenesis** refers to drug-induced fetal malformations and is categorized as a **Type D** (delayed) adverse drug reaction.
- These effects are often severe, occur after prolonged exposure, and are rare.
Adverse Cutaneous Drug Reactions Indian Medical PG Question 6: A 42-year-old man was seen in the clinic because of pain and redness in his finger. Last week he had injured the finger while working in his garage. On physical examination, there is erythema, swelling, and tenderness of the second digit in the right hand. Flexion and extension of the finger were normal. A clinical diagnosis of cellulitis is made and he is prescribed cephalexin. A few days later he presents to the emergency room complaining of difficulty breathing. He has angioedema due to a drug reaction to the cephalexin. Which of the following physical findings is characteristic of this syndrome?
- A. Invariably severe itching
- B. Prolonged nature of the edema
- C. Fluid extravasation from subcutaneous and intradermal postcapillary venules
- D. Involvement of lips, tongue, eyelids, genitalia, and dorsum of hands or feet (Correct Answer)
Adverse Cutaneous Drug Reactions Explanation: ***Involvement of lips, tongue, eyelids, genitalia, and dorsum of hands or feet***
- **Angioedema** is characterized by episodic, localized swelling of the deeper dermal and subcutaneous tissues, often affecting the **lips, tongue, eyelids, genitalia, and dorsum of hands or feet** [1].
- This distribution is due to the **loose connective tissue** in these areas, which allows for significant fluid accumulation.
*Invariably severe itching*
- While angioedema can sometimes be accompanied by itching, **severe itching (pruritus)** is more characteristic of **urticaria** (hives), which involves the superficial dermis [1].
- In many cases of angioedema, particularly **bradykinin-mediated types**, itching is absent or minimal.
*Prolonged nature of the edema*
- The edema in **angioedema** typically resolves within **24 to 72 hours**, not weeks or months, differentiating it from other chronic inflammatory conditions.
- Its self-limiting nature is a key diagnostic feature, although recurrence is common.
*Fluid extravasation from subcutaneous and intradermal postcapillary venules*
- **Fluid extravasation** from postcapillary venules occurs in both urticaria and angioedema. However, in angioedema, the fluid extravasation occurs at the level of the **deep dermis and subcutaneous tissue**, leading to deeper swelling.
- In **urticaria**, the extravasation is more superficial, affecting the **epidermis and superficial dermis**, resulting in itchy wheals.
Adverse Cutaneous Drug Reactions Indian Medical PG Question 7: Which oral hypoglycemic drug causes an Antabuse-like effect?
- A. Chlorpropamide (Correct Answer)
- B. Gliclazide
- C. Acarbose
- D. Metformin
Adverse Cutaneous Drug Reactions Explanation: ***Chlorpropamide***
- Chlorpropamide, a **first-generation sulfonylurea**, can inhibit aldehyde dehydrogenase, leading to the accumulation of **acetaldehyde** when alcohol is consumed.
- This accumulation causes an **Antabuse-like effect**, characterized by flushing, nausea, vomiting, dizziness, and headache.
*Acarbose*
- Acarbose is an **alpha-glucosidase inhibitor** that delays carbohydrate absorption from the gut.
- Its side effects primarily include gastrointestinal disturbances like **flatulence, diarrhea, and abdominal pain**, and it does not cause an Antabuse-like reaction.
*Metformin*
- Metformin, a **biguanide**, primarily works by reducing hepatic glucose production and improving insulin sensitivity.
- Its common side effects are **gastrointestinal upset** (e.g., nausea, diarrhea) and it can rarely cause **lactic acidosis**, but it does not interact with alcohol to produce an Antabuse-like effect.
*Gliclazide*
- Gliclazide is a **second-generation sulfonylurea** that stimulates insulin release from pancreatic beta cells.
- While all sulfonylureas can potentially cause hypoglycemia, gliclazide is less likely to produce a significant Antabuse-like reaction compared to first-generation agents like chlorpropamide.
Adverse Cutaneous Drug Reactions Indian Medical PG Question 8: Which of the following is/are associated with an anaphylactic reaction?
- A. Urticaria & Swollen lips
- B. Hypertension
- C. Persistent abdominal cramps
- D. Both a & c (Correct Answer)
Adverse Cutaneous Drug Reactions Explanation: ***Both a & c***
- Anaphylaxis is a **severe, life-threatening allergic reaction** characterized by rapid onset and diverse symptoms, including cutaneous (urticaria, swollen lips), respiratory, cardiovascular (hypotension, tachycardia), and gastrointestinal symptoms [1].
- **Urticaria (hives)** and **angioedema (swollen lips/face)** are common cutaneous manifestations [2], while **persistent abdominal cramps** can indicate gastrointestinal involvement, all typical of anaphylaxis [1].
*Urticaria & Swollen lips*
- While **urticaria** and **swollen lips (angioedema)** are classic signs of anaphylaxis, they represent only one system involved in severe reactions [1].
- Anaphylaxis is a multi-system reaction, and these symptoms alone do not encompass the full clinical picture or severity [3].
*Hypertension*
- Anaphylaxis primarily causes **hypotension** due to widespread vasodilation and increased vascular permeability, not hypertension.
- **Hypotension** is a key diagnostic criterion for severe anaphylaxis, indicating cardiovascular collapse [1].
*Persistent abdominal cramps*
- **Persistent abdominal cramps** are a recognized gastrointestinal symptom of anaphylaxis, resulting from smooth muscle contraction and fluid shifts [1].
- However, relying solely on this symptom would miss other vital signs and symptoms that define and confirm an anaphylactic reaction.
Adverse Cutaneous Drug Reactions Indian Medical PG Question 9: Which of the following drug classes is commonly implicated in causing Stevens-Johnson syndrome?
- A. Antibiotics (Correct Answer)
- B. Corticosteroids
- C. Antifungals
- D. Proton pump inhibitors
Adverse Cutaneous Drug Reactions Explanation: ***Antibiotics***
- **Antibiotics**, particularly **sulfonamides** (e.g., sulfamethoxazole-trimethoprim) and **beta-lactams** (e.g., penicillins, cephalosporins), are among the most common drug classes implicated in causing **Stevens-Johnson Syndrome (SJS)**.
- SJS is a severe **idiosyncratic drug reaction**, and many antibiotics can trigger this immune-mediated response.
- **Note:** Other major causative drug classes include **anticonvulsants** (carbamazepine, phenytoin, lamotrigine), **allopurinol**, and **NSAIDs**, but among the options listed, antibiotics are the most commonly implicated.
*Corticosteroids*
- **Corticosteroids** are typically used in the **treatment** of SJS to suppress the immune response and reduce inflammation, not to cause it.
- While they have their own set of side effects, initiating SJS is not one of their known adverse reactions.
*Antifungals*
- Although some **antifungals** can cause adverse drug reactions, they are **not typically associated** with SJS compared to antibiotics, anticonvulsants, or allopurinol.
- The risk of SJS with antifungal medications is generally very low.
*Proton pump inhibitors*
- **Proton pump inhibitors (PPIs)** are generally well-tolerated and are **rarely implicated** as a cause of SJS.
- Their primary side effects are usually gastrointestinal and not severe dermatological reactions.
Adverse Cutaneous Drug Reactions Indian Medical PG Question 10: Most common precipitant of contact dermatitis is?
- A. Gold
- B. Silver
- C. Iron
- D. Nickel (Correct Answer)
Adverse Cutaneous Drug Reactions Explanation: ***Nickel***
- **Nickel** is the most frequent cause of **allergic contact dermatitis**, commonly found in jewelry, belt buckles, and zippers.
- Exposure leads to a **Type IV hypersensitivity reaction**, characterized by erythema, itching, and vesiculation.
*Gold*
- While gold can cause contact dermatitis, it is **far less common** than nickel allergy.
- Reactions to gold are often seen with prolonged skin contact, such as with jewelry.
*Silver*
- **Silver** is a **rare cause** of allergic contact dermatitis.
- Allergic reactions to silver are typically observed in individuals with extensive exposure, such as jewelers.
*Iron*
- **Iron** is **not a common precipitant** of contact dermatitis.
- Allergic reactions to iron are exceedingly rare, as iron is an essential element found naturally in the body.
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