Derm Flashcards
Q: What is Acanthosis nigricans?
A: Acanthosis nigricans describes symmetrical, brown, velvety plaques often found on the neck, axilla, and groin.
Q: What is acne vulgaris?
A: Acne vulgaris is a disease of the pilosebaceous unit characterized by multiple types of acne lesions commonly seen in each patient.
Q: What are the common causes of Acanthosis nigricans?
Type 2 diabetes mellitus
Gastrointestinal cancer
Obesity
Polycystic ovarian syndrome
Acromegaly
Cushing’s disease
Hypothyroidism
Familial
Prader-Willi syndrome
Drugs (e.g., combined oral contraceptive pill, nicotinic acid)
Q: What is the pathophysiology of Acanthosis nigricans?
A: The pathophysiology involves insulin resistance → hyperinsulinemia → stimulation of keratinocytes and dermal fibroblast proliferation via interaction with insulin-like growth factor receptor-1 (IGFR1).
Q: What causes comedones in acne vulgaris?
A: Comedones are caused by a dilated sebaceous follicle. A whitehead forms if the top is closed, while a blackhead forms if the top opens.
Q: How do inflammatory lesions develop in acne vulgaris?
A: Inflammatory lesions form when the follicle bursts, releasing irritants, leading to the development of papules and pustules.
Q: What severe complications can result from excessive inflammation in acne vulgaris?
A: Excessive inflammation can lead to nodules, cysts, and ultimately scarring, such as ice-pick scars and hypertrophic scars.
Q: How does drug-induced acne differ from typical acne vulgaris?
A: Drug-induced acne is often monomorphic, with pustules being characteristic, especially in steroid use.
Q: What is acne fulminans, and how is it managed?
A: Acne fulminans is a very severe form of acne associated with systemic symptoms like fever, often requiring hospital admission and typically responding to oral steroids.
Q: What is the pathophysiology of acne vulgaris?
A: Acne vulgaris occurs due to obstruction of pilosebaceous follicles with keratin plugs, leading to comedones, inflammation, and pustules.
Q: How is acne vulgaris classified?
Mild: Open and closed comedones with or without sparse inflammatory lesions.
Moderate: Widespread non-inflammatory lesions and numerous papules and pustules.
Severe: Extensive inflammatory lesions, nodules, pitting, and scarring.
Q: What is the first-line treatment for mild to moderate acne?
A 12-week course of topical combination therapy:
Topical adapalene + benzoyl peroxide
Topical tretinoin + clindamycin
Topical benzoyl peroxide + clindamycin
Topical benzoyl peroxide alone can be used if retinoids or antibiotics are contraindicated.
Q: What is the first-line treatment for moderate to severe acne?
A 12-week course of:
Topical adapalene + benzoyl peroxide + oral lymecycline or doxycycline
Topical azelaic acid + oral lymecycline or doxycycline
Q: What important considerations apply to oral antibiotics in acne treatment?
Avoid tetracyclines in pregnancy, breastfeeding, and children under 12 years.
Minocycline is less preferred due to irreversible pigmentation risk.
Do not use oral antibiotics for more than 6 months except in exceptional cases.
Always co-prescribe a topical retinoid or benzoyl peroxide with oral antibiotics to reduce resistance.
Q: When are combined oral contraceptives (COCPs) used for acne management?
A: COCPs can be an alternative to oral antibiotics in women but should be combined with topical agents. Dianette (co-cyprindiol) may be used second-line due to increased VTE risk and should be limited to 3 months with proper counseling.
Q: When is oral isotretinoin used for acne?
A: Oral isotretinoin is only prescribed under specialist supervision, with pregnancy being a contraindication.
Q: What treatments should be avoided to reduce antibiotic resistance in acne?
Monotherapy with a topical antibiotic
Monotherapy with an oral antibiotic
Combination of a topical and an oral antibiotic
Q: What are the NICE referral criteria for acne?
Refer to a dermatologist if:
Acne conglobata (severe inflammatory nodules and cysts)
Nodulo-cystic acne
Consider referral if:
Mild to moderate acne unresponsive to two treatments
Moderate to severe acne unresponsive to oral antibiotics
Acne with scarring or persistent pigment changes
Acne causing psychological distress
Q: What is acne vulgaris?
A: Acne vulgaris is a common skin disorder affecting the face, neck, and upper trunk, characterized by obstruction of pilosebaceous follicles with keratin plugs, leading to comedones, inflammation, and pustules.
Q: What are the key components of acne vulgaris pathophysiology?
Follicular epidermal hyperproliferation forming a keratin plug that obstructs the pilosebaceous follicle.
Sebaceous gland activity, possibly influenced by androgens (though levels are often normal).
Colonization by Propionibacterium acnes (anaerobic bacterium).
Inflammation.
Q: What are actinic keratoses (AK)?
A: Actinic keratoses (AK) are common premalignant skin lesions caused by chronic sun exposure.
Q: What are the clinical features of actinic keratoses?
Small, crusty or scaly lesions
May be pink, red, brown, or the same color as the skin
Typically found on sun-exposed areas, e.g., temples of the head
Multiple lesions may be present
Q: What are the management options for actinic keratoses?
Prevention: Sun avoidance, sun cream
Fluorouracil cream: 2-3 week course, causing redness and inflammation (topical hydrocortisone may be used after)
Topical diclofenac: For mild AK, moderate efficacy with fewer side effects
Topical imiquimod: Effective based on trials
Cryotherapy
Curettage and cautery
Q: What is alopecia areata?
A: Alopecia areata is a presumed autoimmune condition causing localized, well-demarcated patches of hair loss, often with small, broken ‘exclamation mark’ hairs at the edge of the lesion.