Basic Dermatology Practice Questions

Q: Sebaceous cysts can occur in all the following locations in the body except:

Palms and soles. ***Palms and soles*** - **Sebaceous cysts** (more accurately termed epidermoid cysts) arise from the **epidermis and hair follicle infundibulum**, not from sebaceous glands themselves. - The **palms and soles** lack both sebaceous glands and hair follicles, making these locations impossible for sebaceous cysts to form. - This is a key anatomical distinction used in clinical diagnosis. *Axilla* - The **axilla** contains numerous hair follicles and sebaceous glands, making it a common site for sebaceous cyst formation. - These cysts can become inflamed or infected due to the moist environment, friction, and bacterial flora of the region. - Hormonal influences can also contribute to cyst development in this area. *Back* - The **back** is a very common location for sebaceous cysts due to a high concentration of hair follicles and sebaceous glands. - Cysts in this area can become quite large and are often subject to irritation from clothing. - The back (especially upper back) is one of the most frequent sites for these lesions. *Pubic area* - The **pubic area** is rich in hair follicles and sebaceous glands, making it susceptible to the formation of sebaceous cysts. - **Hormonal activity** and friction can contribute to the development of these cysts in this region. - Inflammation and infection are more common in this area due to occlusion and moisture.

Q: Keratodermic sandals are associated with which of the following conditions?

Pityriasis rubra pilaris. ***Pityriasis rubra pilaris*** - **Keratodermic sandals** describe the characteristic **thickening and orange-red discoloration of the palms and soles** seen in pityriasis rubra pilaris. - This condition also typically presents with **follicular papules** and areas of normal skin (islands of sparing) amidst generalized erythema. *Pityriasis rosea* - Characterized by a **herald patch** followed by an eruption of oval, erythematous, scaly patches on the trunk and proximal extremities, often arranged in a **Christmas tree pattern**. - It does not involve significant palmar or plantar hyperkeratosis. *Lichen planus* - Manifests as **pruritic, purple, polygonal, planar papules and plaques** (the 6 P's), often affecting the wrists, ankles, and oral mucosa. - While it can involve nail changes and sometimes hyperkeratosis, the specific "keratodermic sandals" pattern is not characteristic. *Psoriasis* - Typically presents with well-demarcated, erythematous plaques covered by **silvery scales**, commonly on extensor surfaces, scalp, and nails. - Although palmoplantar psoriasis can occur, it's distinct from the diffuse, orange-red hyperkeratosis described as keratodermic sandals in pityriasis rubra pilaris.

Q: Which skin condition is characterized by a 'Christmas tree' appearance?

Pityriasis rosea. ***Pityriasis rosea*** - This condition classically presents with an eruption of oval, erythematous, slightly scaly papules and plaques arranged in a **'Christmas tree' pattern** along the skin cleavage lines on the trunk. - It often begins with a single larger lesion known as a **'herald patch'** before the generalized eruption. *Pityriasis rubra pilaris* - Characterized by reddish-orange scaling plaques with **follicular papules** and often involves confluence, leading to areas of normal skin called **'islands of sparing.'** - It does not typically form a 'Christmas tree' pattern; instead, it tends to spread cranially from the lower body. *Psoriasis* - Psoriasis typically presents as well-demarcated, erythematous plaques covered with **silvery scales**, often found on extensor surfaces, scalp, and nails. - The distinctive pattern of psoriasis does not involve a 'Christmas tree' distribution; it's more often characterized by symmetrically distributed lesions. *Vitiligo* - Vitiligo is a pigmentary disorder characterized by **depigmented macules and patches** of varying sizes, resulting from the destruction of melanocytes. - It does not involve inflammatory lesions or any specific 'Christmas tree' arrangement.

Q: Which glands are primarily affected by Fox Fordyce Disease?

Apocrine glands. ***Apocrine glands*** - Fox-Fordyce disease is also known as **apocrine miliaria**, directly implicating **apocrine glands** in its pathology. - The disease involves the occlusion of **apocrine duct openings**, leading to rupture of the duct and accumulation of secretory products, causing inflammation and characteristic pruritic papules. *Sebaceous glands* - These glands secrete **sebum** and are primarily affected in conditions like **acne vulgaris** or **sebaceous cysts**, not Fox-Fordyce disease. - While sebaceous glands are present in areas where Fox-Fordyce disease can occur, they are not the primary target of the disease process. *Eccrine Glands* - **Eccrine glands** produce **sweat** for thermoregulation and are affected in conditions like **miliaria crystallina** or **hyperhidrosis**. - Their involvement in Fox-Fordyce disease is secondary or negligible, as the primary pathology is distinct to apocrine structures. *Any gland* - Fox-Fordyce disease specifically targets **apocrine glands**, making a generalized involvement of "any gland" incorrect. - It does not show a predilection for **eccrine** or **sebaceous glands**; the pathology is precise.

Q: What is the color of tuberous sclerosis lesions when examined under a Wood's lamp?

Milky white appearance. ***Milky white appearance*** - Under a Wood's lamp, the **hypopigmented lesions** (ash-leaf spots) of **tuberous sclerosis** appear as a **milky white or chalky white color** due to the lack of melanin. - This accentuation by the Wood's lamp makes the often subtle lesions more visible, aiding in diagnosis. - "Milky white" is the **classic descriptor** used in medical literature for tuberous sclerosis lesions. *Bright greenish hue* - A **bright greenish hue** is typically associated with fungal infections like **tinea capitis** caused by *Microsporum* species, not tuberous sclerosis. - The fluorescence is due to metabolic byproducts of the fungi. *Golden yellowish tint* - A **golden yellowish tint** can be seen in certain bacterial infections, such as those caused by *Corynebacterium minutissimum* in **erythrasma**. - This is not characteristic of melanin deficiency as seen in tuberous sclerosis. *Blue-white glow* - While **hypopigmented lesions in general** (including vitiligo) may appear bright or enhanced under Wood's lamp, the **classic and preferred clinical descriptor** for tuberous sclerosis ash-leaf spots is specifically **"milky white" or "chalky white"**. - The distinction is based on **standard medical terminology** rather than visual color difference, as hypopigmented conditions show similar enhancement patterns. - Tuberous sclerosis is diagnosed based on **characteristic leaf-shaped morphology, distribution, and associated systemic features**, not just Wood's lamp appearance alone.

Q: Which of the following statements is true regarding Acanthosis Nigricans?

Is associated with insulin resistant diabetes mellitus.. ***Is associated with insulin resistant diabetes mellitus.*** - **Acanthosis nigricans** is a common cutaneous marker of **insulin resistance**, frequently seen in patients with **type 2 diabetes mellitus** or prediabetes. - The increased insulin levels stimulate **keratinocyte** and **fibroblast growth factors**, leading to the characteristic skin changes. *Is characterized by hypopigmentation.* - Acanthosis nigricans is characterized by **hyperpigmentation**, presenting as dark, velvety patches, not hypopigmentation. - The darkening of the skin is due to increased melanin production and epidermal thickening. *Commonly occurs in individuals who are lean and thin.* - While it can occur in lean individuals, acanthosis nigricans is **most commonly associated with obesity** and being overweight. - The strong link to **insulin resistance** means it is more prevalent in individuals with higher body mass indices. *Is not typically associated with skin malignancy.* - This statement is **incorrect** - acanthosis nigricans **can be associated with malignancy** as a **paraneoplastic syndrome**, particularly when it has an abrupt onset, rapid progression, or atypical distribution. - It is most commonly associated with **gastrointestinal adenocarcinomas** (e.g., stomach, colon) and sometimes lung or breast cancer.

Q: Identify the skin condition depicted in the image.

Ichthyosis. ***Ichthyosis*** - The image clearly displays widespread **dry, scaling, and thickened skin**, consistent with the characteristic presentation of ichthyosis. - This condition is characterized by a defect in **skin barrier function** leading to excessive dryness and accumulation of scales. *Syndromic ichthyosis* - While syndromic ichthyosis also involves skin scaling, it is associated with **additional systemic symptoms** or **organ involvement**, which cannot be determined from this image alone. - The term "ichthyosis" broadly covers this appearance, and without more clinical information, specifying it as syndromic is not the most direct identification. *Leprosy* - Leprosy typically presents with **hypopigmented, anesthetic skin patches** or **nodules**, which are not seen in the image. - The texture and color changes in the image are not characteristic of the primarily neurological and dermatological manifestations of leprosy. *Cutaneous sarcoidosis* - Cutaneous sarcoidosis manifests as **reddish-brown papules, plaques, or nodules**, often on the face, neck, or extremities. - The widespread, fine scaling and dryness seen in the image do not align with the typical granulomatous lesions of sarcoidosis.

Q: Cutis marmorata occurs due to exposure to –

Cold temperature. ***Cold temperature*** - **Cutis marmorata** is a physiological response to **cold temperatures**, characterized by a mottled, reticulated vascular pattern on the skin. - This occurs due to **vasoconstriction** of the small arteries and arterioles, alongside **vasodilation** of the venules, creating the characteristic marbled appearance. *Dust* - Exposure to **dust** typically causes **irritation**, allergic reactions, or respiratory issues, such as **dermatitis**, **contact urticaria**, or **asthma**. - It does not directly lead to the characteristic vascular changes seen in cutis marmorata. *Hot temperature* - **Hot temperatures** generally cause **vasodilation** in the skin to facilitate **heat dissipation**, leading to redness and warmth. - This is the opposite physiological response to cutis marmorata, which involves vasoconstriction. *Humidity* - **Humidity** primarily affects **skin hydration** and the rate of perspiration, potentially exacerbating certain skin conditions like **eczema** or **fungal infections**. - High or low humidity does not directly induce the vascular changes that result in cutis marmorata.

Q: Identify the type of skin lesion shown in the image.

Macule. ***Macule*** - The lesion shown is a **macule**, characterized by being **flat and circumscribed** with no elevation above the skin surface. - A macule is defined as a **skin discoloration less than 1 cm in diameter** without any palpable change in texture or thickness. - Classic examples include **freckles, flat nevi, and café-au-lait spots**. - The image demonstrates the typical appearance with clear borders and no vertical component. *Papule* - A papule is an **elevated, solid lesion less than 1 cm** in diameter. - Unlike the lesion shown, papules have a **palpable raised component** above the skin surface. - Examples include acne, warts, and lichen planus. *Patch* - A patch is similar to a macule but is **larger than 1 cm in diameter**. - While also flat, the size criterion differentiates it from a macule. - Examples include vitiligo patches and large birthmarks. *Nodule* - A nodule is a **solid, elevated lesion greater than 1 cm** that extends into deeper skin layers. - It has both elevation and depth, unlike the flat lesion shown. - Examples include dermatofibromas, lipomas, and some cysts.

Q: What do the Lines of Blaschko represent?

Patterns of cell migration. ***Patterns of cell migration*** - The **Lines of Blaschko** are invisible patterns in the skin reflecting the **movement and proliferation of cells** during embryonic development. - They become apparent in certain genetic conditions or mosaics when affected cells form streaks or swirls following these lines. *Patterns along lymphatics* - **Lymphatic patterns** refer to the distribution of the lymphatic system, which drains interstitial fluid and immune cells. - Skin conditions involving lymphatics often present as **lymphedema** or **lymphangitis**, which do not typically follow Blaschko's lines. *Patterns along blood vessels* - **Vascular patterns** describe the distribution of blood vessels in the skin, which can be affected in conditions like **livedo reticularis** or **vasculitis**. - These are distinct from Blaschko's lines, which are embryological in origin and not directly related to vascular anatomy. *Patterns along nerves* - **Nerve patterns** in the skin, such as **dermatomes**, correspond to the sensory innervation supplied by spinal nerves. - While some skin conditions can follow dermatomal distributions (e.g., **herpes zoster**), these are distinct from the embryological migration patterns represented by Blaschko's lines.

Question 1

Sebaceous cysts can occur in all the following locations in the body except:

Accepted Answer

Palms and soles

Answer

Back

Answer

Pubic area

Answer

Axilla

Question 2

Keratodermic sandals are associated with which of the following conditions?

Accepted Answer

Pityriasis rubra pilaris

Answer

Lichen planus

Answer

Psoriasis

Answer

Pityriasis rosea

Question 3

Which skin condition is characterized by a 'Christmas tree' appearance?

Accepted Answer

Pityriasis rosea

Answer

Pityriasis rubra pilaris

Answer

Psoriasis

Answer

Vitiligo

Question 4

Which glands are primarily affected by Fox Fordyce Disease?

Accepted Answer

Apocrine glands

Answer

Sebaceous glands

Answer

Eccrine glands

Answer

Any gland

Question 5

What is the color of tuberous sclerosis lesions when examined under a Wood's lamp?

Accepted Answer

Milky white appearance

Answer

Bright greenish hue

Answer

Golden yellowish tint

Answer

Blue-white glow

Question 6

Which of the following statements is true regarding Acanthosis Nigricans?

Accepted Answer

Is associated with insulin resistant diabetes mellitus.

Answer

Is characterized by hypopigmentation.

Answer

Commonly occurs in individuals who are lean and thin.

Answer

Is not typically associated with skin malignancy.

Question 7

Identify the skin condition depicted in the image.

Accepted Answer

Ichthyosis

Answer

Syndromic ichthyosis

Answer

Cutaneous sarcoidosis

Answer

Leprosy

Question 8

Cutis marmorata occurs due to exposure to –

Accepted Answer

Cold temperature

Answer

Dust

Answer

Hot temperature

Answer

Humidity

Question 9

Identify the type of skin lesion shown in the image.

Accepted Answer

Macule

Answer

Papule

Answer

Patch

Answer

Nodule

Question 10

What do the Lines of Blaschko represent?

Accepted Answer

Patterns of cell migration

Answer

Patterns along lymphatics

Answer

Patterns along blood vessels

Answer

Patterns along nerves

Basic Dermatology — MCQs

Basic Dermatology — MCQs

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