1. In the epidermis:

Answer: A. In normal skin, stratum corneum is formed of nucleated cells.
Explanation:

• A. In normal skin, stratum corneum is formed of nucleated cells: Incorrect. The stratum corneum consists of dead, non-nucleated keratinized cells in normal skin.

• B. In mucous membranes, stratum corneum is very thick: Incorrect. In mucous membranes, the stratum corneum is typically thin or absent.

• C. All layers are derived from the basal cell layer: Correct. The basal layer (stratum basale) is responsible for the proliferation of keratinocytes, giving rise to all epidermal layers.

• D. Blood vessels are numerous: Incorrect. The epidermis is avascular, relying on diffusion from the dermis for nutrients and oxygen.

• E. There are no other cells than keratinocytes: Incorrect. The epidermis contains melanocytes, Langerhans cells, and Merkel cells, in addition to keratinocytes.

2. In the epidermis, all these cells are normally present EXCEPT:

Answer: C. Lymphocyte.
Explanation:

• A. Keratinocyte: Correct. Keratinocytes are the predominant cells in the epidermis, forming its structure.

• B. Melanocyte: Correct. Melanocytes are present in the basal layer and produce melanin.

• C. Lymphocyte: Incorrect. Lymphocytes are not typically found in the epidermis; they are part of the immune system and more common in the dermis or during inflammatory conditions.

• D. Langerhans' cell: Correct. These are dendritic immune cells in the epidermis.

• E. Corneocyte (corneal layer cell): Correct. Corneocytes are the keratinized cells of the stratum corneum.

3. The basal cell layer of the epidermis is composed of:

Answer: D. Papillary cells.
Explanation:

• A. A single layer of non-nucleated cells: Incorrect. The basal layer consists of nucleated cells that divide and give rise to keratinocytes.

• B. Three rows of dividing cells: Incorrect. The basal layer is a single row of dividing cells.

• C. Cells filled with keratin: Incorrect. Keratin is present in the upper layers, like the stratum corneum, not the basal layer.

• D. Papillary cells: Correct. The basal layer contains basal keratinocytes responsible for epidermal regeneration.

• E. Hair follicles: Incorrect. Hair follicles are part of the dermis and extend into the hypodermis.

4. The dermis:

Answer: C. Divided into papillary layer and reticular layer.
Explanation:

• A. Composed of non-nucleated cells: Incorrect. The dermis contains nucleated cells, such as fibroblasts, macrophages, and mast cells.

• B. Melanocytes, which give the skin its color, are found in the dermis: Incorrect. Melanocytes are located in the epidermis, specifically in the basal layer.

• C. Divided into papillary layer and reticular layer: Correct. The dermis is divided into two layers: the upper papillary layer and the deeper reticular layer.

• D. Blood vessels are rarely found here; they are numerous in the epidermis: Incorrect. The dermis is highly vascularized, unlike the epidermis, which lacks blood vessels.

• E. Is thicker in palms and soles: Correct. The dermis is indeed thicker in these areas, providing extra strength and cushioning.

5. The Keratinization process:

Answer: D. Is the travel of cells from basal layer to corneal layer with formation of keratin.
Explanation:

• A. Is the process of cell division that occurs in the corneal layer: Incorrect. Cell division occurs in the basal layer, not the corneal layer.

• B. Is the process of losing keratin that takes 28 days: Incorrect. Keratinization is about keratin formation, not loss.

• C. Normally takes hours rather than days: Incorrect. Keratinization typically takes around 28 days, from cell production to desquamation.

• D. Is the travel of cells from basal layer to corneal layer with formation of keratin: Correct. This describes the keratinization process accurately.

• E. While cells travel upward, cell organelles increase in size: Incorrect. Cell organelles degrade as cells move upwards and become keratinized.

6. Primary skin lesions include:

Answer: C. Macule.
Explanation:

• A. Hyperkeratosis: Incorrect. Hyperkeratosis is a histopathological finding, not a primary lesion.

• B. Erosion: Incorrect. Erosion is a secondary lesion that results from the loss of the epidermis.

• C. Macule: Correct. A macule is a flat, distinct, discolored area of skin that is a primary lesion.

• D. Ulcers: Incorrect. Ulcers are secondary lesions caused by loss of epidermis and dermis.

• E. Lichenification: Incorrect. Lichenification is a secondary lesion caused by chronic rubbing or scratching.

7. Secondary skin lesions include:

Answer: E. Excoriations.
Explanation:

• A. Papule: Incorrect. A papule is a primary lesion characterized by a small, solid, raised lesion.

• B. Vesicle: Incorrect. A vesicle is a primary lesion filled with clear fluid.

• C. Pustule: Incorrect. A pustule is a primary lesion filled with pus.

• D. Plaque: Incorrect. A plaque is a primary lesion, typically raised and greater than 1 cm.

• E. Excoriations: Correct. Excoriations are secondary lesions caused by scratching or trauma, leading to the loss of the epidermis.

8. Hyperkeratosis means:

Answer: E. Increase in the thickness of stratum corneum.
Explanation:

• A. Decrease in the thickness of the epidermis: Incorrect. Hyperkeratosis involves thickening, not thinning, of the epidermis.

• B. Increase in the thickness of the dermis: Incorrect. Hyperkeratosis affects the stratum corneum, not the dermis.

• C. Increase in the thickness of the whole epidermis: Incorrect. Hyperkeratosis is specific to the stratum corneum layer.

• D. Increase in the thickness of basal cell layer: Incorrect. The basal layer is not involved in hyperkeratosis.

• E. Increase in the thickness of stratum corneum: Correct. Hyperkeratosis refers to an abnormal thickening of the stratum corneum, often seen in conditions like psoriasis or calluses.

9. Lichenification means:

Answer: C. Increase in the thickness of the whole epidermis.
Explanation:

• A. Decrease in the thickness of the epidermis: Incorrect. Lichenification involves thickening, not thinning.

• B. Increase in the thickness of the dermis: Incorrect. Lichenification occurs in the epidermis, not the dermis.

• C. Increase in the thickness of the whole epidermis: Correct. Lichenification is a chronic skin change resulting from repeated scratching or rubbing, causing thickening of the epidermis and accentuation of skin markings.

• D. Increase in the thickness of basal cell layer: Incorrect. While basal cell activity may increase, the term primarily refers to the entire epidermis.

• E. Increase in the thickness of stratum corneum: Incorrect. Though the stratum corneum may thicken, lichenification involves all layers of the epidermis.

10. Crust is defined as:

Answer: A. Collection of dried exudates and cellular debris.
Explanation:

• A. Collection of dried exudates and cellular debris: Correct. A crust forms when serum, blood, or pus dries on the skin surface, commonly seen in impetigo or eczema.

• B. Collection of clear fluid of more than 5 mm: Incorrect. This describes a bulla, not a crust.

• C. Presence of pus regardless of the size: Incorrect. Pus characterizes pustules, not crusts.

• D. Depressed lesion of the skin: Incorrect. Depressed lesions are typically erosions or ulcers.

• E. Superficial loss of epidermal continuity: Incorrect. This defines erosion, not crust.

11. Erosion is:

Answer: D. Loss of continuity of the surface layers of the skin.
Explanation:

• A. Thinning of the skin: Incorrect. Thinning refers to atrophy, not erosion.

• B. Thickening of the stratum corneum: Incorrect. Thickening is related to hyperkeratosis, not erosion.

• C. Post-inflammatory hypopigmentation: Incorrect. This is a pigmentary change, not a lesion.

• D. Loss of continuity of the surface layers of the skin: Correct. Erosion involves superficial loss of the epidermis without extending to the dermis.

• E. Vertical loss of continuity of layers of the skin: Incorrect. This describes an ulcer, not an erosion.

12. Tinea corporis:

Answer: C. Dermatophyte infection of all glabrous skin excluding palms, soles, and groin.
Explanation:

• A. Is a self-limiting disease: Incorrect. Tinea corporis is not self-limiting and requires antifungal treatment.

• B. Patch of localized loss of hair covered with fine scales: Incorrect. This describes tinea capitis, not tinea corporis.

• C. Dermatophyte infection of all glabrous skin excluding palms, soles, and groin: Correct. Tinea corporis affects smooth, hairless skin, excluding the mentioned areas.

• D. Typical lesion is a hypopigmented patch with unclear margins: Incorrect. Tinea lesions are often erythematous, scaly, and have well-demarcated borders.

• E. Typical lesion is a plaque covered with silvery scales: Incorrect. This describes psoriasis, not tinea corporis.

13. Tinea capitis:

Answer: E. Diagnosis is confirmed by KOH examination.
Explanation:

• A. Is the dermatophyte infection of beard and moustache: Incorrect. This describes tinea barbae, not tinea capitis.

• B. Typical lesion is a plaque covered with crusted hair: Incorrect. While crusting may occur, this is not a defining characteristic.

• C. Topical antifungal (imidazoles or miconazole) is enough to treat the condition: Incorrect. Tinea capitis often requires systemic antifungal therapy.

• D. Treatment is by topical and systemic antibiotics: Incorrect. Antibiotics are ineffective against fungal infections.

• E. Diagnosis is confirmed by KOH examination: Correct. Potassium hydroxide (KOH) preparation is a standard diagnostic test for fungal infections.

14. Systemic antifungal is essential in the treatment of:

Answer: D. Tinea unguinum & Tinea cruris.
Explanation:

• A. Tinea unguinum: Incorrect. While systemic antifungals are needed, this option alone is incomplete.

• B. Tinea cruris: Incorrect. Tinea cruris often responds to topical antifungals unless severe.

• C. Tinea capitis: Incorrect. Though systemic antifungals are essential, this option alone is incomplete.

• D. Tinea unguinum & Tinea cruris: Correct. Systemic antifungals are required for tinea unguinum (onychomycosis) and extensive cases of tinea cruris.

• E. Tinea unguinum & Tinea capitis: Incorrect. While both require systemic antifungals, this option omits tinea cruris.

15. The causative organism of Herpes zoster is:

Answer: C. Varicella-zoster virus
Explanation:

• A. Herpes simplex virus: Incorrect. This causes herpes simplex infections, like cold sores or genital herpes.

• B. Herpes-zoster virus: Incorrect. This is a misnomer; the actual causative agent is the Varicella-zoster virus.

• C. Varicella-zoster virus: Correct. Herpes zoster (shingles) is caused by the reactivation of the Varicella-zoster virus, which also causes chickenpox.

• D. Coryno-bacterium: Incorrect. This refers to a genus of bacteria, not viruses.

• E. Unknown: Incorrect. The causative agent is well known.

16. Herpes zoster:

Answer: E. The causative virus is dormant in the posterior root ganglia after a chickenpox infection.
Explanation:

• A. Appears as generalized vesicle: Incorrect. Herpes zoster presents as localized vesicles in a dermatomal distribution.

• B. Affects individuals in middle age with good immunity: Incorrect. It commonly affects immunocompromised individuals or the elderly.

• C. Herpetic neuralgia may precede vesicle appearance: Incorrect. Although postherpetic neuralgia is a known complication, it doesn’t typically precede the rash.

• D. Affected individuals have past history of Herpes simplex infection: Incorrect. Herpes zoster is linked to a past Varicella-zoster infection, not herpes simplex.

• E. The causative virus is dormant in the posterior root ganglia after a chickenpox infection: Correct. This is the hallmark of Herpes zoster pathogenesis.

17. Viral warts can be treated with all of these methods EXCEPT:

Answer: E. Highly potent topical steroids
Explanation:

• A. Cautery and electrical burn: Correct. Effective for wart removal.

• B. Chemical destruction: Correct. Topical agents like salicylic acid can destroy warts.

• C. Cryotherapy by liquid nitrogen: Correct. A standard treatment method for warts.

• D. Removal by curette: Correct. Warts can be surgically excised.

• E. Highly potent topical steroids: Incorrect. Steroids are not effective against viral warts as they suppress inflammation, not viral replication.

18. Kerion is:

Answer: C. Fungal infection of the scalp, being a complication of Tinea capitis
Explanation:

• A. Bacterial infection of the hair follicles especially of lower limbs: Incorrect. Kerion is fungal, not bacterial.

• B. Parasitic infection of the scalp associated with pediculosis: Incorrect. Pediculosis is caused by lice, not fungi.

• C. Fungal infection of the scalp, being a complication of Tinea capitis: Correct. Kerion is an inflammatory reaction to fungal infections of the scalp, often caused by dermatophytes.

• D. A painful genital ulcer: Incorrect. This describes chancroid or herpes, not kerion.

• E. A viral infection of the skin: Incorrect. Kerion is fungal, not viral.

19. Pityriasis rosea:

Answer: C. Usually starts with the characteristic herald (mother) patch
Explanation:

• A. Appears as painful plaque in the trunk: Incorrect. Pityriasis rosea is not painful; it presents as scaly patches.

• B. If not treated, complications are not preventable: Incorrect. Pityriasis rosea is self-limiting and complications are rare.

• C. Usually starts with the characteristic herald (mother) patch: Correct. This is the typical presentation, with a large patch preceding smaller lesions.

• D. Systemic steroids is the available treatment: Incorrect. Steroids are not usually required as the condition resolves on its own.

• E. Topical antifungal is the best treatment: Incorrect. Pityriasis rosea is not fungal in origin.

20. The causative parasite of scabies is:

Answer: E. Sarcoptes species
Explanation:

• A. Treponema pallidum: Incorrect. This is the causative agent of syphilis, not scabies.

• B. Pediculus humanus: Incorrect. This is the causative agent of lice infestations.

• C. Haemophilus ducreyi: Incorrect. This causes chancroid, not scabies.

• D. Leishmania donovani: Incorrect. This is the causative agent of visceral leishmaniasis (kala-azar).

• E. Sarcoptes species: Correct. Scabies is caused by Sarcoptes scabiei mite.

21. The following skin diseases are caused by viruses EXCEPT:

Answer: B. Impetigo contagiosum
Explanation:

• A. Molluscum contagiosum: Correct. Caused by a poxvirus.

• B. Impetigo contagiosum: Incorrect. Impetigo is caused by bacterial agents like Staphylococcus aureus or Streptococcus pyogenes.

• C. Warts: Correct. Caused by human papillomavirus (HPV).

• D. Herpes zoster: Correct. Caused by the Varicella-zoster virus.

• E. Chickenpox: Correct. Also caused by the Varicella-zoster virus.

22. Acne vulgaris:

Answer: C. Apart from the face it may involve chest and shoulders
Explanation:

• A. A disease of sweat glands: Incorrect. Acne vulgaris originates from sebaceous glands, not sweat glands.

• B. Although it appears with puberty, hormonal changes of adolescence has no role: Incorrect. Hormonal changes play a significant role in acne development.

• C. Apart from the face it may involve chest and shoulders: Correct. Acne commonly affects sebaceous-rich areas like the face, chest, and back.

• D. Topical or systemic antibiotics has no role in treatment: Incorrect. Antibiotics are an important treatment option for inflammatory acne.

• E. Required no treatment: Incorrect. While mild acne may not require intervention, moderate to severe cases need treatment.

23. The pathogenesis of Acne vulgaris:

Answer: D. Blockage of sebaceous glands by keratin
Explanation:

• A. Decreased sweating mainly in hot seasons: Incorrect. Acne is not related to sweat glands but to sebaceous glands.

• B. Increased in submucosa glands of basal cells: Incorrect. This is not a factor in acne pathogenesis.

• C. Inflammation of the turn-over of keratin: Incorrect. While keratin turnover plays a role, inflammation alone does not explain the full pathogenesis.

• D. Blockage of sebaceous glands by keratin: Correct. Acne develops when keratin and sebum block the sebaceous glands, leading to comedone formation and secondary inflammation.

• E. Pytyrosporum ovale (Malassezia furfur): Incorrect. This organism is implicated in Pityriasis versicolor, not acne.

24. Pityrosporum ovale (Malassezia furfur):

Answer: E. All of the above
Explanation:

• A. Is the causative organism for Pityriasis versicolor: Correct. Malassezia furfur is the causative agent of Pityriasis versicolor.

• B. Triggers hypopigmentation of scalp dandruff: Correct. It is associated with dandruff and sometimes hypopigmented areas.

• C. Causes hyper- or hypo-pigmented plaques: Correct. This is a hallmark of Pityriasis versicolor.

• D. Is the causative organism for Pityriasis versicolor: Correct. Reiterates the organism’s role.

• E. All of the above: Correct. This combines all correct statements.

25. Molluscum Contagiosum:

Answer: C. In adults, is commonly transmitted by sexual contact
Explanation:

• A. A specific name, it is not contagious: Incorrect. The name indicates it is contagious, and it is caused by a poxvirus.

• B. Typically occurs in children: Partially correct. While common in children, this option ignores the fact that adults can be affected.

• C. In adults, is commonly transmitted by sexual contact: Correct. Adults often acquire it through sexual transmission, especially in the genital region.

• D. Lesions are usually antiviral, sun-protected parts: Incorrect. Lesions are not limited to sun-protected parts.

• E. Treatment is by topical antiviral, sun-protected parts: Incorrect. Antivirals are not the treatment; physical removal methods like cryotherapy are preferred.

26. Tinea incognito:

Answer: B. Obscure lesions of tinea corporis due to the use of topical corticosteroids
Explanation:

• A. Typical lesions of tinea corporis infection: Incorrect. The lesions are not typical due to steroid use.

• B. Obscure lesions of tinea corporis due to the use of topical corticosteroids: Correct. Tinea incognito occurs when corticosteroids suppress the inflammation but allow fungal growth to continue, leading to atypical presentations.

• C. Super-infection commonly will affect the condition: Incorrect. Superinfection is not a defining feature.

• D. Is a yeast infection the body will treat the condition: Incorrect. It is caused by dermatophytes, not yeast.

• E. Impetigo contagiosum: Incorrect. This refers to a bacterial infection, not tinea.

27. Impetigo contagiosum:

Answer: A. Caused by Staphylococcus or Streptococcus
Explanation:

• A. Caused by Staphylococcus or Streptococcus: Correct. Impetigo is caused by Staphylococcus aureus or Streptococcus pyogenes.

• B. Lesions are usually in the palms and soles: Incorrect. Lesions are typically on the face and extremities, not the palms and soles.

• C. Systemic treatment must be used in all cases: Incorrect. Systemic treatment is reserved for severe cases; mild cases are treated topically.

• D. Adults are more affected: Incorrect. Impetigo is more common in children.

• E. Its degree will help selection of the best treatment: Partially correct. Treatment depends on severity, but this is not the best option.

28. Auspitz sign in psoriasis:

Answer: D. Mechanical removal of scales results in pin-point bleeding
Explanation:

• A. Adults will have more selection of the best treatment: Incorrect. This does not describe the Auspitz sign.

• B. Not recommended in children: Incorrect. The sign is not dependent on age.

• C. Usually negative in plaque-type psoriasis: Incorrect. The Auspitz sign is typically positive in psoriasis.

• D. Mechanical removal of scales results in pin-point bleeding: Correct. This is the hallmark of the Auspitz sign, characteristic of psoriasis.

• E. Appearance of generalized itchy silvery scales: Incorrect. While this describes psoriasis, it does not explain the Auspitz sign.

29. Eleven years old female child with localized loss of scalp hair and dome-shaped lesion in the brother:

Answer: C. Taenia capitis must be excluded by KOH examination in both conditions
Explanation:

• A. These are two different diagnosis that are not area related: Incorrect. Both are likely related to fungal infections.

• B. The first differential diagnosis is Alopecia areata: Incorrect. Alopecia areata does not present with scales or yellow crusts.

• C. Taenia capitis must be excluded by KOH examination in both conditions: Correct. Tinea capitis is the most likely diagnosis and requires confirmation by KOH examination.

• D. Topical treatment is excluded, because it never occurs in females: Incorrect. Tinea capitis affects both genders.

• E. Topical antibiotics is required in both conditions: Incorrect. Antibiotics are ineffective against fungal infections.

30. Chickenpox:

Answer: D. Appear as vesicles preceded by fever
Explanation:

• A. Caused by pox virus: Incorrect. Chickenpox is caused by the Varicella-zoster virus, not a poxvirus.

• B. The treatment of choice is low potency topical steroids: Incorrect. Treatment is usually supportive, with antiviral therapy in severe cases.

• C. Is not infectious: Incorrect. Chickenpox is highly contagious.

• D. Appear as vesicles preceded by fever: Correct. This describes the classical presentation of chickenpox.

• E. Appears as generalized itchy silvery scales: Incorrect. This describes psoriasis, not chickenpox.