Dermatology and Skin Disease Concepts - Practice Flashcards

A comprehensive set of practice flashcards covering dermatology topics from acne to urticaria, including conditions, pathophysiology, presentation, diagnosis, and management based on the provided lecture notes.

What causes the murmur of a venous hum observed in exam questions?

Turbulent flow in the jugular veins.

What are the four pathogenic factors in acne vulgaris involving the pilosebaceous unit?

Increased sebum, hyperkeratinization, Propionibacterium acnes (P. acnes) colonization, and inflammation.

What is a hallmark lesion type commonly seen in acne vulgaris?

Comedones (whiteheads/blackheads).

How is mild acne typically managed at first?

Topical retinoid and benzoyl peroxide used at different times; add a topical antibiotic (e.g., clindamycin or erythromycin) while continuing retinoid.

When should topical antibiotics for acne be reassessed or stopped?

At about three months.

What are the oral options for moderate to severe acne?

Oral antibiotics, oral contraceptives, or spironolactone, depending on acne features.

What is the definitive, highly effective but teratogenic treatment option for severe acne?

Oral isotretinoin.

Which organism most commonly causes folliculitis, and which one is classic for hot tub folliculitis?

Staphylococcus aureus; Pseudomonas for hot tub folliculitis.

What is a first-line management approach for initial folliculitis?

Benzoyl peroxide wash; topical antibiotics such as mupirocin or clindamycin; MRSA coverage if needed.

Which feature is pathognomonic of rosacea in many patients?

Facial flushing.

Which mite is often increased in number in rosacea and thought to contribute to its pathophysiology?

Demodex mites.

What topical agent is used to treat facial redness and telangiectasia in rosacea?

Topical vasoconstrictor such as brimonidine gel.

What is the first-line topical treatment for rosacea with papules and pustules?

Topical metronidazole.

How can rosacea with rhinophyma be treated?

Oral tetracyclines or isotretinoin; lasers or surgery for deformities.

What is erythema multiforme and where are target lesions most commonly seen?

Inflammation with target-shaped lesions, commonly on the hands and extremities.

What is the most common cause of erythema multiforme?

Herpes simplex virus (HSV).

How do you distinguish SJS/TEN from milder drug eruptions in terms of body surface area involvement?

SJS involves

What sign is classically positive in Stevens-Johnson syndrome and toxic epidermal necrolysis?

Nikolsky sign (skin shears off with slight pressure).

Which age group is most affected by Staphylococcal Scalded Skin Syndrome (SSSS)?

Young children, usually around ages 2–3.

What is a key differentiating factor between SSSS and SJS/TEN?

SSSS typically has no mucous membrane involvement; SJS/TEN involve mucous membranes.

In androgenic alopecia, what is the first-line topical treatment?

Minoxidil.

Which medication can be added to minoxidil for men or used in women with androgenic alopecia?

Finasteride (and sometimes spironolactone in women).

What is alopecia areata characterized by and what is a common first-line therapy?

Autoimmune patchy hair loss with exclamation point hairs; intralesional corticosteroids as first-line therapy.

What is the most common causative organism in onychomycosis?

Dermatophyte Trichophyton rubrum.

What is a key diagnostic step for onychomycosis to improve sensitivity?

Nail clipping with fungal culture and a potassium hydroxide (KOH) prep (often two tests: culture plus KOH).

How is acute paronychia typically managed initially?

Warm compresses; topical antibiotics; incision and drainage if there is an abscess.

What bite is classically associated with necrosis in the skin and what is the typical management?

Brown recluse bite; immobilization, ice, elevation, anti-staphylococcal antibiotics, and tetanus prophylaxis.

What type of neurotoxic symptoms are associated with widow spider bites and how are they managed?

Muscle pain, spasms, weakness, tremors; managed with wound care, analgesia, IV opioids/benzodiazepines for severe pain, antivenom if severe, and tetanus prophylaxis.

Which bites/injuries have high infection risk requiring amoxicillin-clavulanate therapy, particularly for cat bites?

Cat bites (Pasteurella species are common); aggressive wound care and antibiotics.

How are cellulitis and erysipelas characterized in terms of borders and causative organisms?

Cellulitis: deeper infection with less distinct borders; erysipelas: superficial with well-demarcated borders; both commonly due to beta-hemolytic streptococcus.

What is the initial treatment for mild cellulitis?

Dicloxacillin or cephalexin; for more severe cases, parenteral antibiotics with MRSA coverage as needed.

What are the two main forms of impetigo and their typical causative agents?

Non-bullous impetigo (honey-colored crusts) and bullous impetigo; Staphylococcus aureus is common; streptococcal involvement possible.

What is the primary management for an abscess that is drainable?

Incision and drainage; culture if severe or systemic symptoms; antibiotics based on severity and MRSA risk.

What is theSuggested immediate management for a suspected necrotizing soft tissue infection?

Emergent surgical consult for exploration and debridement; rapid resuscitation; broad-spectrum antibiotics (penicillin, clindamycin, metronidazole with an aminoglycoside).

Which organism is most associated with mucosal candidiasis and what is a common treatment for vulvovaginal candidiasis?

Candida albicans; single-dose oral fluconazole (or topical azoles for less invasive disease).

What are the common diagnostic steps and treatment options for tinea infections (dermatophytes)?

KOH prep and culture; topical antifungals (terbinafine, itraconazole, fluconazole) for most; systemic therapy for tinea capitis/barbate.

How is pediculosis (head lice) diagnosed and treated?

Live lice and nits near the scalp; treated with 1% permethrin; wet combing; oral ivermectin for refractory cases.

What is the clinical hallmark of scabies and its treatment options?

Intense nocturnal itching with papules and burrows, especially around wrists and webs; treated with permethrin 5% cream, or lindane, or oral ivermectin; treat close contacts.

What diseases are warts caused by and how are common warts (verruca vulgaris) treated?

Human papillomavirus (HPV 2 and 4); treated with lesion destruction methods such as salicylic acid, cryotherapy, liquid nitrogen, or laser/surgical removal.

Which HPV types cause genital warts (condyloma acuminata) and how are they managed?

HPV types 6 and 11; observation is possible; topical imiquimod, cryotherapy, or surgical excision for larger lesions.

What is molluscum contagiosum and its typical management in children?

Poxvirus causing waxy, umbilicated papules; usually self-limited; management includes curettage, cryotherapy, or chemical cautery.

What are the typical presentations of HSV-1 vs HSV-2 and their primary treatments?

HSV-1: gingivostomatitis and herpes labialis; HSV-2: genital herpes; diagnosed by PCR; treated with antivirals (episodic or suppressive depending on frequency).

What is the clinical presentation of shingles (reactivated varicella zoster virus)?

Unilateral dermatomal vesicular rash with neuropathic pain; prodrome; diagnose clinically; treat with antivirals for 5–7 days.

How is hand, foot, and mouth disease caused and what areas are typically involved?

Caused by Coxsackieviruses; stomatitis with vesicular rash on hands and feet and sometimes the mouth and genitals; supportive care.

What is actinic keratosis and how is it treated?

Precancerous crusty, rough lesions that can progress to squamous cell carcinoma; treated with cryotherapy; field therapy with 5-FU or imiquimod; biopsy if atypical.

What are seborrheic keratoses and how are they typically managed?

Benign, 'stuck-on' waxy lesions; common with age; usually observation; removal for cosmetic reasons via cryotherapy, curettage, or excision.

What is the typical presentation and treatment for basal cell carcinoma?

Pearly, translucent papule/nodule with rolled borders and telangiectasia; biopsy for diagnosis; treatment with excisional biopsy, electrodesiccation and curettage, or Mohs surgery; rare metastasis.

What differentiates squamous cell carcinoma from basal cell carcinoma in terms of risk factors and behavior?

SCC arises from keratinocytes with deeper invasion; higher risk with UV exposure, organ transplant, HPV, arsenic; treated with excision or Mohs; may require nodal assessment in high-risk cases.

What are the ABCDE features of melanoma and the significance of Breslow depth?

A: Asymmetry; B: Border irregular; C: Color variegation; D: Diameter >5 mm; E: Evolution/elevation; Ugly duckling sign; Breslow depth is the strongest prognostic factor.

Which melanoma subtype is most common and characterized by radial growth?

Superficial spreading melanoma; radial growth phase improves prognosis.

Which melanoma subtype is common in darker-skinned individuals and occurs on palms/soles?

Acral lentiginous melanoma.

What is Kaposi sarcoma and what virus is involved?

Dark violaceous nodules/plaques in immunocompromised patients; associated with HHV-8.

What is lichen planus and its characteristic features (the five P’s)?

Pruritic, Purple, Polygonal, Planar, Papules/plaques; frequent mucosal involvement and Koebner phenomenon; associated with hepatitis C.

What is pityriasis rosea and its typical pattern?

Self-limited exanthem with herald patch followed by salmon-colored plaques in a Christmas tree distribution; likely HHV-6/HHV-7; rule out syphilis.

What triggers and signs are characteristic of psoriasis, including Koebner and Auspitz signs?

Chronic plaque psoriasis with pink/red plaques and silvery scales; Koebner phenomenon (trauma-triggered lesions); Auspitz sign (pinpoint bleeding on scale removal); triggers include streptococcal infection, smoking, obesity.

What causes melasma and how is it best managed?

Hormonal factors (pregnancy, OCP) with sun exposure; treated with sun protection and topical agents (hydroquinone, tretinoin, steroids) for epidermal melasma.

What is vitiligo and how is it managed?

Autoimmune depigmentation of melanocytes with symmetric depigmented patches; managed with topical calcineurin inhibitors, phototherapy (narrowband UV), and sunscreen; sometimes combination therapy.

What distinguishes tinea versicolor from vitiligo and what organism causes it?

Hypo- or hyperpigmented patches with fine scaling in sebaceous areas caused by Malassezia furfur; diagnosed with KOH prep showing hyphae and yeast; treated with fluconazole and topical antifungals; pigmentation may take months to normalize.

What are the burn depth categories and the critical 48-hour window in burn care?

Superficial (epidermis only), superficial partial thickness (pink, blistering), deep partial thickness (white, wet with pain), full thickness (white/charred, no sensation); first 48 hours are critical for progression and infection risk.

What is the Parkland formula for initial fluid resuscitation in burns?

Lactated Ringer’s solution: 4 mL × body weight (kg) × %TBSA burned; half in first 8 hours from time of injury; remaining over the next 16 hours.

Where are pilonidal disease lesions typically located and who is most at risk?

Superior aspect of the natal cleft; more common in teenage/young adult males, especially if overweight or seated for long periods.

What is trench foot and what are its risk factors and management principles?

Non-freezing cold injury from prolonged exposure to cold, wet conditions; risk factors include homelessness, alcohol use; management emphasizes drying, gradual rewarming, elevation, and prevention.

What is a non-freezing cold injury (chilblains) and its management?

Red to violaceous lesions triggered by cold exposure; management includes rest, warmth, skin protection, and prevention.

What are the key steps in laceration repair and the timing for primary vs delayed closure?

Hemostasis, debridement, irrigation, anesthesia; primary closure within 12–18 hours for clean, sharp wounds; delayed primary closure around day 3–4 for contaminated wounds or high-risk patients.

What are common risk factors for pressure ulcers and core management principles?

Immobility, decreased sensation, incontinence, poor nutrition; use pressure-relieving devices, wound debridement, skin grafting for significant ulcers, and appropriate dressings.

What is a hallmark of diabetic foot ulcers and the essential steps in management?

Ulcers with a surrounding ring of callus, risk of deeper infection; assess vascular status; offload weight-bearing; debridement, dressings, infection control, glycemic control, and vascular referral if needed.

What is stasis dermatitis and its management strategy?

Dermatitis due to venous insufficiency with edema; treat with elevation, compression therapy, emollients, and anti-inflammatory/topical steroids.

What is a cherry angioma and what is a key safety consideration?

Benign bright red dome-shaped papule; common in 30s–40s and on trunk/upper limbs; sudden onset of many may warrant evaluation for internal malignancy.

What are telangiectasias and common associations or treatments?

Superficial dilated vessels; associated with rosacea, pregnancy, steroids; treated with laser or electrocautery if bothersome.

What are the distinguishing features and Nikolsky sign in pemphigus vulgaris vs pemphigoid?

Pemphigus vulgaris: younger adults; flaccid bullae with mucosal involvement; positive Nikolsky; immunofluorescence; treated with steroids/immunosuppressives. Pemphigoid: elderly; more stable bullae; less mucosal involvement; negative Nikolsky; treated with steroids/immunosuppressives.

What is acanthosis nigricans and its clinical associations?

Hyperpigmented, velvety plaques in flexural areas; associated with obesity, insulin resistance, diabetes; sometimes linked to medications or malignancies.

What characterizes hidradenitis suppurativa (HS) and typical management strategies?

Chronic inflammatory disease of apocrine glands with painful nodules, abscesses, and sinus tracts; common in axillae/genital area; associated with smoking, obesity; management includes antibiotics, TNF inhibitors, and sometimes surgery.

What are lipomas and their typical management approach?

Benign subcutaneous fat tumors; soft, mobile, non-tender, slow-growing; managed with observation or surgical excision if symptomatic.

What are epidermal inclusion cysts and how are inflamed cysts managed?

Benign cysts from upper hair follicle; central punctum; can drain; inflamed lesions may need incision and drainage with steroid injection.

What is the difference between phototoxic and photoallergic reactions and their management?

Phototoxic: nonimmune, immediate, localized to sun-exposed areas; phototoxic agents (e.g., some antibiotics); Photoallergic: immune-mediated, delayed, may extend beyond exposure; stop agent, protect from sun, topical or systemic steroids as needed.

Where are most pilonidal disease abscesses located and what is key in their management?

In the superior gluteal crease (natal cleft area); management includes incision and drainage with packing, oral antibiotics as needed, wound care, and prevention of recurrence.

What is urticaria and how is it managed acutely vs chronically?

Wheals (hives) that are usually pruritic; acute urticaria is often self-limited; chronic urticaria has unclear etiology. Management includes second-generation antihistamines; higher doses if refractory; add first-generation antihistamines if needed; epinephrine for anaphylaxis.

What is the typical cause and management of pityriasis rosea?

Likely HHV-6/HHV-7; herald patch followed by Christmas tree pattern rash; self-limited; rule out secondary syphilis.

What are the key features and management of actinic keratosis?

Rough, crusty precancerous lesions with potential progression to squamous cell carcinoma; cryotherapy; field therapy with 5-FU or imiquimod; biopsy for atypical features.

What is the typical presentation of basal cell carcinoma and preferred management options?

Pearly, translucent papule/nodule with rolled border and telangiectasia; head/neck common; managed by excisional biopsy, electrodesiccation and curettage, Mohs surgery; topical 5-FU can be used in select cases.

How is cutaneous squamous cell carcinoma characterized and treated?

Proliferation of keratinocytes with dermal invasion; risk factors include UV exposure, transplant, HPV, arsenic; treatment includes surgical excision or Mohs surgery; may require sentinel lymph node evaluation for high-risk lesions.

What is the single most important prognostic factor in melanoma?

Breslow depth (tumor depth).

What are the main melanoma precursor lesions discussed and their significance?

Dysplastic (atypical) nevi and congenital melanocytic nevi; potential evolution to melanoma; monitor and biopsy atypical lesions.

What are the major melanoma subtypes and where are they commonly located?

Superficial spreading (most common; trunk in men, legs in women); nodular (poor prognosis; rapid depth); lentigo maligna (older adults, face); acral lentiginous (palms/soles, often in darker-skinned individuals).

What is Kaposi sarcoma and what virus is involved?

Immunocompromised patients develop dark violaceous nodules/ plaques; associated with HHV-8 (human herpesvirus 8).

What are the common skin signs of lichen planus and the Koebner phenomenon?

Five P’s: pruritic, purple, polygonal, planar, papules/plaques; mucosal involvement common; Koebner phenomenon (trauma triggers lesions).

What is the clinical pattern of herpes simplex virus (HSV) infections and their management strategies?

HSV-1 commonly causes oral lesions; HSV-2 commonly causes genital ulcers; diagnosed by PCR; treated with antiviral therapy (episodic or suppressive based on frequency).

What is the typical progression and management of hand, foot, and mouth disease?

Stomatitis with vesicular rash on hands/feet; caused by Coxsackieviruses; supportive care.

What is the diagnostic approach and treatment for tinea versicolor?

KOH prep showing yeast with hyphae and thick-walled budding spores; treated with oral fluconazole (two doses 14 days apart) and topical antifungals; patient education about slow normalization of pigmentation.

What are common presentations and treatments for pityriasis versicolor?

Hypo- or hyperpigmented patches with fine scaling in sebaceous areas; Malassezia furfur; treated with antifungals (fluconazole, ketoconazole) and sun protection.

What is the key clinical feature of actinic keratosis that signals risk of progression to squamous cell carcinoma?

Rough, crusty lesions in sun-exposed areas; risk of progression to squamous cell carcinoma; cryotherapy or field-directed therapies recommended.

What is the typical management for melanomas that are stage 1–2 vs stage 3–4?

Stage 1–2: surgical excision with possible adjuvant therapy; Stage 3: regional metastasis may receive immunotherapy; Stage 4: metastasis may involve surgery, radiotherapy, immunotherapy, or chemotherapy.

What is the recommended management for a suspected necrotizing soft tissue infection beyond initial imaging to avoid delays?

Urgent surgical consultation and exploration; broad-spectrum antibiotics; aggressive fluid resuscitation and supportive care.

What is the standard initial management for a wound laceration to reduce infection risk and optimize healing?

Hemostasis, debridement, irrigation, anesthesia; timely closure (primary within 12–18 hours for clean wounds; <12 hours for higher-risk or contaminated wounds).