Dermatological Examination Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Dermatological Examination. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Dermatological Examination Indian Medical PG Question 1: Identify the skin lesion shown in the image.
- A. Becker nevus (Correct Answer)
- B. Hypopigmented macule
- C. Spitz nevus
- D. Epidermal nevus
Dermatological Examination Explanation: ***Becker nevus***
- This image clearly shows a large, **hyperpigmented patch with overlying coarse terminal hairs**, characteristic of a Becker nevus.
- Becker nevi typically develop in adolescence and are often found on the shoulder or upper trunk, as seen here.
*Hypopigmented macule*
- A **hypopigmented macule** would appear as an area of skin with **reduced pigmentation** (lighter than the surrounding skin), which is contrary to the darker lesion shown.
- There would also be no indication of **increased hair growth** within a typical hypopigmented macule.
*Spitz nevus*
- A Spitz nevus is a benign melanocytic nevus often appearing as a **dome-shaped, pink or red papule or nodule**, commonly on the face or limbs.
- It does not present as a large, hairy, **hyperpigmented patch** as depicted in the image.
*Epidermal nevus*
- An epidermal nevus is a **congenital lesion** formed by an overgrowth of epidermal cells, but its appearance is typically a **verrucous (wart-like) plaque** or linearly arranged papules.
- While it can be hyperpigmented, it generally **lacks the prominent hypertrichosis** (excessive hair growth) seen in the image.
Dermatological Examination Indian Medical PG Question 2: Diascopy is very helpful in the diagnosis of:
- A. Lupus vulgaris
- B. Cutaneous vasculitis
- C. Nevus anaemicus
- D. All of the options (Correct Answer)
Dermatological Examination 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).
Dermatological Examination Indian Medical PG Question 3: A child has a rash. His family history is positive for asthma. What could be the most probable diagnosis?
- A. Seborrheic dermatitis
- B. Atopic dermatitis (Correct Answer)
- C. Allergic contact dermatitis
- D. Erysipelas
Dermatological Examination Explanation: ***Atopic dermatitis***
- The presence of a rash in a child with a family history of **asthma** strongly suggests atopic dermatitis, as it is part of the **atopic triad** (eczema, asthma, allergic rhinitis).
- Atopic dermatitis often presents with **erythematous, pruritic patches** and plaques, commonly affecting flexural areas like the antecubital and popliteal fossae, as well as the face and neck in younger children.
*Seborrheic dermatitis*
- This condition typically presents with **greasy, yellowish scales** on an erythematous base, often affecting areas rich in sebaceous glands such as the scalp, face (nasolabial folds), and chest.
- While it can occur in infants, it does not have the strong association with a family history of asthma seen in atopic dermatitis.
*Allergic contact dermatitis*
- This rash results from an **exposure to an allergen**, leading to a localized, erythematous, and pruritic eruption, often with vesicles or bullae, at the site of contact.
- The history does not provide information about a specific allergen exposure, and while it could produce a similar-looking rash, the family history of asthma points more strongly to atopic diathesis.
*Erysipelas*
- Erysipelas is a superficial skin infection, usually caused by *Streptococcus pyogenes*, presenting as a **well-demarcated, intensely erythematous, warm, and painful rash** with a raised border.
- This is an **acute bacterial infection** and would typically be accompanied by systemic symptoms like fever and chills, which are not mentioned in the child's presentation.
Dermatological Examination Indian Medical PG Question 4: A 30-year-old male presented with silvery scales on elbow and knee, that bleed on removal. The probable diagnosis is:
- A. Secondary syphilis
- B. Psoriasis (Correct Answer)
- C. Pityriasis
- D. Seborrhoeic dermatitis
Dermatological Examination Explanation: ***Psoriasis***
- The presence of **silvery scales** on the elbows and knees, which **bleed upon removal** (Auspitz sign), is a classic presentation of **plaque psoriasis**.
- Psoriasis is a chronic inflammatory skin condition characterized by **accelerated epidermal turnover**.
*Secondary syphilis*
- Secondary syphilis typically presents with a **generalized maculopapular rash**, which can affect the palms and soles, but it does not usually feature silvery scales or the Auspitz sign.
- Other common symptoms of secondary syphilis include **fever, lymphadenopathy, and condyloma lata**.
*Pityriasis*
- **Pityriasis rosea** is characterized by an oval, fawn-colored, scaly rash, often preceded by a **herald patch**, and usually resolves spontaneously. It does not typically present with silvery scales or bleeding on removal.
- **Pityriasis versicolor** is caused by yeast and presents as hypopigmented or hyperpigmented macules with fine scales, commonly on the trunk, not silvery scales on elbows and knees.
*Seborrhoeic dermatitis*
- Seborrhoeic dermatitis involves greasy, yellowish scales on red skin, typically affecting areas rich in sebaceous glands like the scalp, face (nasolabial folds, eyebrows), and chest.
- It does not present with silvery scales or the Auspitz sign, which are specific to psoriasis.
Dermatological Examination Indian Medical PG Question 5: Koebner's phenomenon seen in ?
- A. Lichen nitidus
- B. Psoriasis
- C. All of the options (Correct Answer)
- D. Vitiligo
Dermatological Examination Explanation: ***All of the options***
- **Koebner's phenomenon** (isomorphic response) refers to the development of new lesions at sites of **skin trauma** in patients with pre-existing dermatological conditions.
- **All four conditions listed** can exhibit Koebner's phenomenon, making this the correct answer.
**Psoriasis**
- The **most classic and frequently cited** example of Koebner's phenomenon.
- Physical injury triggers characteristic red, scaly plaques at trauma sites.
- Seen in approximately **25-50%** of psoriasis patients.
**Vitiligo**
- Well-documented to exhibit **Koebner's phenomenon**.
- New **depigmented patches** appear at sites of trauma, cuts, or friction.
- Important diagnostic and prognostic indicator in vitiligo patients.
**Lichen planus**
- Classic condition showing **Koebner's phenomenon**.
- New violaceous, flat-topped papules develop at trauma sites.
- One of the hallmark features of this condition.
**Lichen nitidus**
- Although less commonly emphasized, **Lichen nitidus can exhibit Koebner's phenomenon**.
- Tiny, shiny papules may appear in linear distribution following trauma.
- Part of the lichenoid reaction group that shows isomorphic response.
Dermatological Examination Indian Medical PG Question 6: Which of the following methods is used for demonstrating old washed bloodstains?
- A. Infrared photography
- B. Luminol spray (Correct Answer)
- C. Magnifying lens
- D. Ultraviolet light
Dermatological Examination Explanation: **Luminol spray**
- **Luminol** reacts with the iron in **hemoglobin** to produce a blue-white luminescence, making it highly effective for detecting even heavily diluted or rinsed-away bloodstains.
- It is particularly useful for demonstrating **old, washed-up bloodstains** at crime scenes where visual identification might be difficult.
*Infrared photography*
- While useful for detecting certain hidden details or substances, **infrared photography** is not the primary method for revealing old or washed-up bloodstains.
- **Bloodstains** can absorb infrared light to varying degrees, but the chemical reaction of luminol is specifically designed for trace blood detection.
*Magnifying lens*
- A **magnifying lens** merely enhances the visibility of existing stains or patterns and cannot detect traces of blood invisible to the naked eye, particularly old or diluted ones.
- It is a tool for closer inspection, not for chemical detection of hidden substances.
*Ultraviolet light*
- **Ultraviolet (UV) light** can be used to detect certain biological fluids such as semen or saliva, which **fluoresce** under UV.
- However, fresh or old bloodstains typically *absorb* UV light rather than fluoresce, making it less effective for detecting them, especially if they are washed up.
Dermatological Examination Indian Medical PG Question 7: A farmer presented with a black mole on the cheek. It increased in size, more than 6mm with irregular borders and a central black lesion, what could be the diagnosis?
- A. Superficial spreading melanoma (Correct Answer)
- B. Acral lentigo melanoma
- C. Lentigo maligna melanoma
- D. Nodular melanoma
Dermatological Examination Explanation: ***Superficial spreading melanoma***
- This is the most common type of melanoma and often presents as a **mole with irregular borders**, varying colors, and a diameter greater than 6mm, consistent with the description.
- The lesion typically grows **radially** across the skin surface before beginning vertical growth, indicated by the increase in size.
*Acral lentigo melanoma*
- This type of melanoma primarily affects the **palms, soles, and nail beds**, which is inconsistent with a lesion on the cheek.
- It often appears as a **dark brown or black patch** that slowly enlarges, but its location is characteristic.
*Lentigo maligna melanoma*
- This melanoma typically occurs in **chronically sun-damaged skin** of the elderly, often on the head and neck, but usually presents as a **flat, irregularly shaped, tan or brown patch** with varying shades, which may not fit the description of a central black lesion within a larger mole.
- It has a dominant **radial growth phase** and progresses slowly over many years before developing a nodular component.
*Nodular melanoma*
- This type is characterized by its **rapid vertical growth** and appearance as a **raised, dark, often dome-shaped lesion** from the outset.
- While it can be black, the description of an "increased in size" mole with irregular borders and a central black lesion points more towards a spreading type rather than a rapidly growing nodule from the beginning.
Dermatological Examination Indian Medical PG Question 8: Dyskeratosis refers to which of the following?
- A. Abnormal, premature keratinization within cells below the stratum granulosum. (Correct Answer)
- B. Discontinuity of the skin showing incomplete loss of epidermis.
- C. Keratinization with retained nuclei in the stratum corneum.
- D. Thickening of stratum corneum, often associated with a qualitative abnormality of keratin.
Dermatological Examination Explanation: ***Abnormal, premature keratinization within cells below the stratum granulosum.***
- **Dyskeratosis** is a histological term for **premature keratinization** of individual keratinocytes.
- This typically occurs in cells that are *below* the **stratum granulosum**, often in the stratum spinosum, indicating abnormal differentiation.
*Discontinuity of the skin showing incomplete loss of epidermis.*
- This description refers to an **erosion** or **ulceration**, depending on the depth of the epidermal loss.
- It does not specifically describe abnormal cellular keratinization.
*Keratinization with retained nuclei in the stratum corneum.*
- This is the definition of **parakeratosis**, which is a normal finding in mucous membranes but an abnormal finding in skin, often associated with disorders like **psoriasis**.
- It indicates incomplete maturation of keratinocytes as they reach the stratum corneum.
*Thickening of stratum corneum, often associated with a qualitative abnormality of keratin.*
- This describes **hyperkeratosis**, which is an increase in the thickness of the **stratum corneum**.
- While it can involve abnormal keratin, it refers to increased thickness, not premature individual cell keratinization.
Dermatological Examination Indian Medical PG Question 9: 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
Dermatological Examination 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.
Dermatological Examination Indian Medical PG Question 10: In a patient with the following lesion on scalp, what changes are seen in the nails?
- A. Azure nails
- B. Dorsal pterygium of nails
- C. Pitting of nails (Correct Answer)
- D. Yellow nail discolouration
Dermatological Examination Explanation: ***Pitting of nails***
- The image shows a patch of **alopecia areata** on the scalp. **Nail pitting** is the most common and characteristic nail change associated with alopecia areata, occurring in **10-66% of cases**.
- Pitting appears as small depressions or **"ice-pick" marks** on the nail surface, resulting from defective nail matrix keratinization.
- Other nail changes in alopecia areata include **trachyonychia (rough nails), red spotted lunulae, onycholysis**, and **Beau's lines**.
*Dorsal pterygium of nails*
- **Dorsal pterygium** occurs when the proximal nail fold fuses with and extends over the nail plate, creating a wing-like scar.
- This is classically associated with **lichen planus, trauma, burns, vasculitis**, and **graft-versus-host disease** — **NOT alopecia areata**.
- It can lead to permanent nail dystrophy or nail loss.
*Azure nails*
- **Azure nails** (blue nails) are typically associated with **Wilson's disease** (copper accumulation) or **minocycline use**, not alopecia areata.
- They represent a blue-gray discoloration of the nail bed or lunula.
*Yellow nail discolouration*
- **Yellow nail syndrome** is a rare condition characterized by slow-growing, thickened, yellow nails, often associated with **lymphedema** and **respiratory problems** (pleural effusions, chronic bronchitis).
- It is not linked to alopecia areata.
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