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Questions and Answers
Which of the following is NOT a characteristic of papules?
Which of the following is NOT a characteristic of papules?
Macules are elevated lesions that can be felt when touched.
Macules are elevated lesions that can be felt when touched.
False
Give an example of a condition that may present with vesicles.
Give an example of a condition that may present with vesicles.
Chickenpox
A _____ is a solid, raised lesion that extends deeper into the skin, typically greater than 1 cm in size.
A _____ is a solid, raised lesion that extends deeper into the skin, typically greater than 1 cm in size.
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Match the following lesions with their descriptions:
Match the following lesions with their descriptions:
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What are bulla?
What are bulla?
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What is the primary pigment found in dark skin that provides greater UV protection?
What is the primary pigment found in dark skin that provides greater UV protection?
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How does the epidermal thickness in dark skin compare to that in white skin?
How does the epidermal thickness in dark skin compare to that in white skin?
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What type of melanin is primarily responsible for lighter skin tones?
What type of melanin is primarily responsible for lighter skin tones?
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Which type of secondary lesion is characterized by a moist surface due to the loss of the epidermis?
Which type of secondary lesion is characterized by a moist surface due to the loss of the epidermis?
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Name one common type of secondary skin lesion associated with chronic scratching.
Name one common type of secondary skin lesion associated with chronic scratching.
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Match the following types of secondary lesions with their descriptions:
Match the following types of secondary lesions with their descriptions:
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How do melanosomes differ in appearance between light and dark skin?
How do melanosomes differ in appearance between light and dark skin?
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What distinct characteristic describes melanosomes in dark skin?
What distinct characteristic describes melanosomes in dark skin?
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What is a key characteristic of scale lesions?
What is a key characteristic of scale lesions?
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Which condition is associated with honey-colored crusts?
Which condition is associated with honey-colored crusts?
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In terms of coloration, crusts associated with purulent exudate are typically what color?
In terms of coloration, crusts associated with purulent exudate are typically what color?
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What associated symptom is common with scales resulting from psoriasis?
What associated symptom is common with scales resulting from psoriasis?
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What is the main feature of parakeratosis?
What is the main feature of parakeratosis?
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Which condition is characterized by spongiosis?
Which condition is characterized by spongiosis?
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_________ is characterized by elongated epidermis and hyperplasia.
_________ is characterized by elongated epidermis and hyperplasia.
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What defines spongiosis in the epidermis?
What defines spongiosis in the epidermis?
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Which condition is characterized by papillomatosis?
Which condition is characterized by papillomatosis?
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Match the following conditions with their corresponding features:
Match the following conditions with their corresponding features:
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What best describes hyperkeratosis?
What best describes hyperkeratosis?
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Which feature is typical of parakeratosis?
Which feature is typical of parakeratosis?
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Acantholysis results in what specific change in the epidermis?
Acantholysis results in what specific change in the epidermis?
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Match the following skin conditions with their definitions:
Match the following skin conditions with their definitions:
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Match the following skin conditions with their characteristics:
Match the following skin conditions with their characteristics:
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Match the following conditions with their associated features:
Match the following conditions with their associated features:
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Match the following terms with their definitions:
Match the following terms with their definitions:
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Match the following conditions to their primary characteristics:
Match the following conditions to their primary characteristics:
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Match the following terms with their descriptions:
Match the following terms with their descriptions:
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Study Notes
Primary Skin Lesions
-
Macules
- Flat, distinct, discolored areas of skin.
- Size: Lesions less than 1 cm.
- Color: Can be different from surrounding skin (e.g., brown, red, white).
- Example: Freckles, flat moles.
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Papules
- Small, raised, solid lesions.
- Size: Less than 1 cm in diameter.
- Texture: Can be smooth or rough.
- Example: Warts, insect bites.
-
Vesicles
- Small, fluid-filled blisters.
- Size: Less than 1 cm.
- Contents: Clear fluid, sometimes serous.
- Example: Chickenpox, herpes simplex.
-
Nodules
- Solid, raised lesions that extend deeper into the skin.
- Size: Greater than 1 cm.
- Texture: Firm; can be painful or not.
- Example: Lipomas, cysts.
-
Pustules
- Raised lesions filled with pus.
- Size: Variable but typically small.
- Characteristics: Red base with yellow or white center.
- Example: Acne, folliculitis.
-
Plaques
- Elevated, flat lesions with a larger surface area.
- Size: Greater than 1 cm.
- Texture: Can be scaly or smooth.
- Example: Psoriasis, eczema.
-
Bulla
- Large, fluid-filled blisters.
- Size: Greater than 1 cm.
- Contents: Clear or serous fluid.
- Example: Burn blisters, pemphigus vulgaris.
Macules
- Flat, distinct, discolored areas of skin
- Less than 1 cm in size
- Can be brown, red, or white
- Examples: Freckles, flat moles
Papules
- Small, raised, solid lesions
- Less than 1 cm in diameter
- Can be smooth or rough
- Examples: Warts, insect bites
Vesicles
- Small, fluid-filled blisters
- Less than 1 cm in size
- Contain clear fluid, sometimes serous
- Examples: Chickenpox, herpes simplex
Nodules
- Solid, raised lesions that extend deeper into the skin
- Greater than 1 cm in size
- Can be firm and painful or not
- Examples: Lipomas, cysts
Pustules
- Raised lesions filled with pus
- Variable in size, typically small
- Have a red base with a yellow or white center
- Examples: Acne, folliculitis
Plaques
- Elevated, flat lesions with a larger surface area
- Greater than 1 cm in size
- Can be scaly or smooth
- Examples: Psoriasis, eczema
Bulla
- Large, fluid-filled blisters
- Greater than 1 cm in size
- Contain clear or serous fluid
- Examples: Burn blisters, pemphigus vulgaris
Melanin Types
- Eumelanin is a brown-black pigment found in higher concentrations in dark skin.
- Phaeomelanin is a yellow-red pigment found in higher concentrations in lighter skin.
Melanin Distribution and Skin Color
- Dark skin has a higher concentration of eumelanin, providing increased protection against UV radiation.
- White skin has lower melanin levels and a more uneven distribution.
Epidermal Thickness
- Dark skin generally has a thicker epidermis than white skin.
- Increased epidermal thickness in dark skin improves barrier function and UV protection.
- Both skin types have similar layers (stratum corneum, stratum granulosum, etc.), but dark skin often exhibits a more pronounced stratum corneum.
Eumelanin and Phaeomelanin Function
- Eumelanin offers greater UV protection and contributes to the dark skin tone.
- Phaeomelanin provides less UV protection and is responsible for lighter skin tones with a reddish/yellow hue.
- Eumelanin helps in minimizing sunburn risk and skin damage.
- Phaeomelanin has a higher risk of phototoxicity under UV exposure.
Key Differences
- The main histological differences between white and dark skin relate to melanin concentration, distribution, epidermal thickness, and the balance of eumelanin and phaeomelanin.
- Understanding these differences is essential for comprehending skin health, disease susceptibility, and the effects of UV exposure.
Types of Secondary Skin Lesions
- Secondary skin lesions are skin changes that develop due to primary lesions being irritated, infected or injured
- Crusts are a result of dried pus, blood or serum on the skin's surface
- Scale refers to flaky skin caused by shedding
- Erosions are when the epidermis is lost and a moist surface is left
- A Ulcer is a deeper loss of skin penetrating the dermis
- Fissures are linear cracks in the skin's surface
- Lichenification is thickening of the skin often caused by chronic scratching or irritation
- Atrophy occurs when the skin is thinned or dermal tissue is lost
- Keloids are raised scars caused by excessive collagen during healing
- Scars are fibrous tissue that replaces normal tissue following an injury
Eumelanin and Phaeomelanin
- Eumelanin is the most common type of melanin, which gives skin a dark pigmentation, like black or brown
- Eumelanin is found in high quantities in the hair and skin
- Eumelanin provides protection from UV radiation
- Phaeomelanin is responsible for lighter pigmentation, like yellow or red
- This type of melanin is most commonly found in people with blonde or red hair, and lighter skin
- Phaeomelanin offers less protection from UV radiation
- The ratio of eumelanin to phaeomelanin in the skin determines a person's skin tone, and how sensitive their skin is to UV damage and skin conditions
Melanosome Distribution in Skin
- Melanosomes are smaller and clustered in groups in light skin.
- Melanosomes are larger, dispersed individually, and evenly distributed in dark skin.
Scale and Crust Lesions
- Definition: Secondary skin changes resulting from primary skin conditions or lesions.
-
Scale:
- Flakes or layers of shed skin, varying in size and thickness.
- Common in conditions like psoriasis, eczema, and fungal infections.
-
Crust:
- Dried serum, blood, or pus, forming a hard, dry layer on the skin.
- Indicative of infection or inflammatory process.
-
Color Variations:
- Scales can be white, yellow, or brownish depending on the underlying condition.
- Crusts may be yellow (purulent) or reddish-brown (hemorrhagic).
-
Texture:
- Scales can be fine or thick, smooth or rough.
- Crusts are often firm or gritty.
-
Common Conditions with Scales:
- Psoriasis: Characterized by silvery-white scales.
- Seborrheic Dermatitis: Flaky scales with greasy or yellow crusts.
- Tinea (Fungal infections): Often displays scaly patches.
-
Common Conditions with Crusts:
- Impetigo: Honey-colored crusts often found in children.
-
Associated Symptoms:
- Itching is common with scales from conditions like psoriasis or eczema.
- Pain or tenderness may accompany crusted lesions when inflamed or infected.
-
Distribution:
- Can be localized (specific areas) or generalized (widespread).
- Common areas for scales include scalp, face, and extremities.
- Crusts may appear anywhere with lesions.
-
Diagnosis:
- Careful history and physical examination are crucial.
- Consideration of underlying systemic issues or skin diseases is necessary for treatment planning.
Spongiosis
- Intercellular edema (swelling) within the epidermis
- Characteristic of eczema
Acanthosis
- Elongated epidermis due to hyperplasia (increased cell growth)
- Diffuse epidermal hyperplasia
Hyperkeratosis
- Loss of keratin attachment from desmosomes (cell-to-cell adhesion structures)
- Increase in keratin content
Parakeratosis
- Retention of nucleated keratinocytes (immature cells) in the stratum corneum (outermost layer of epidermis)
- Lack of maturation time for keratinocytes
- Characteristic of psoriasis
Acantholysis
- Loss of attachment between keratinocytes
- Occurs in pemphigus and impetigo
- Impetigo presents with honey-colored crusts
Papillomatosis
- Projection of dermal papillae (projections of connective tissue) above the surface
- Characteristic of verrucae (warts)
Spongiosis
- Characterized by intercellular edema of the epidermis.
- Exclusively found in eczema.
Acanthosis
- Elongated epidermis due to hyperplasia.
- Diffuse epidermal hyperplasia.
Hyperkeratosis
- Disruption of desmosomes leads to a loss of keratin attachment.
- Results in an increase in keratin content.
Parakeratosis
- Retention of nucleated keratinocytes in the stratum corneum.
- Caused by a lack of maturation time.
- Associated with psoriasis.
Acantholysis
- Loss of attachment between keratinocytes.
- Found in pemphigus and impetigo.
- Impetigo is characterized by honey-colored crusts.
Papillomatosis
- Projection of dermal papillae above the surface.
- Characteristic of verrucae (warts).
Spongiosis
- Intercellular edema of the epidermis
- Exclusively found in eczema
Acanthosis
- Elongated epidermis, caused by epidermal hyperplasia
- Diffuse epidermal hyperplasia
Hyperkeratosis
- Loss of keratin attachment due to disruption of desmosomes
- Increase in keratin content
Parakeratosis
- Retention of nucleated keratinocytes in the stratum corneum
- Lack of adequate maturation time
- Characteristic of psoriasis
Acantholysis
- Loss of attachment between keratinocytes
- Associated with pemphigus and impetigo
- Impetigo is characterized by honey-colored crusts
Papillomatosis
- Projection of dermal papillae above the surface
- Characteristic of verrucae (warts)
Spongiosis
- Intercellular oedema of the epidermis
- Unique to eczema
Acanthosis
- Elongated epidermis due to hyperplasia
- Diffuse epidermal hyperplasia
Hyperkeratosis
- Increased thickness of the stratum corneum
Parakeratosis
- Retention of nucleated keratinocytes in the stratum corneum
- Occurs due to lack of maturation time
- A common feature of psoriasis
Acantholysis
- Loss of attachment between keratinocytes
- Characteristic of pemphigus
- Also present in impetigo which exhibits honey-colored crusts
Papillomatosis
- Projection of dermal papillae above the surface
- Seen in verrucae (warts)
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