Dermatology Flashcards
(82 cards)
1
Q
Macule vs patch
A
Macule: flat, < 1 cm, change in skin colour only (e.g., freckle)
Patch: flat, > 1 cm (e.g., vitiligo)
2
Q
Papule vs Nodule vs Plaque
A
Papule: raised, solid, < 1 cm (e.g., insect bite)
Nodule: raised, solid, > 1 cm, deeper than papule (e.g., dermatofibroma)
Plaque: raised, flat-topped, > 1 cm, often formed by coalescence of papules (e.g., psoriasis)
3
Q
Vesicle vs Bulla vs Pustule
A
Vesicle: fluid-filled, < 1 cm (e.g., herpes simplex)
Bulla: fluid-filled, > 1 cm (e.g., bullous pemphigoid)
Pustule: pus-filled (e.g., acne)
4
Q
Wheal:
A
- transient,
- raised,
- itchy,
- often allergic (e.g., urticaria)
5
Q
Scale vs crust
A
Scale: flakes of stratum corneum (e.g., psoriasis)
Crust: dried serum/blood (e.g., impetigo)
6
Q
fissure vs Ulcer
A
Ulcer: full-thickness loss of epidermis and dermis (e.g., leg ulcer)
Fissure: linear crack (e.g., eczema)
7
Q
Impetigo features
A
- Superficial bacterial infection, often Staph aureus or Strep pyogenes
- Golden/crusted lesions, typically around nose/mouth
- Non-bullous (more common) vs bullous (S. aureus toxin-mediated)
- Contagious, especially in children
Swab if widespread
8
Q
Impetigo mx
A
- Localised: topical fusidic acid 2% (5–7 days)
- Widespread/bullous: oral flucloxacillin (clarithromycin if pen-allergic)
- Advise on school: no school until lesions crusted/dried or 48h after starting abx
9
Q
Folliculitis features + mx
A
- Superficial pustules centered on hair follicles
- Often due to S. aureus
- Can be itchy or tender
- Mx
- Mild: hygiene advice, antiseptic washes (e.g. chlorhexidine)
- More severe: topical antibiotics (fusidic acid), or oral flucloxacillin if extensive
10
Q
Cellulitis features
A
- Unilateral, red, hot, swollen area with poorly defined border
- Fever, systemic symptoms
- Often lower limbs, may involve lymphangitis
- Important: bilateral leg redness is unlikely to be cellulitis
11
Q
Cellulitis invx
A
Consider FBC, CRP, blood cultures if unwell/systemic signs
12
Q
Cellulitis mx
A
Primary Care:
1. Oral flucloxacillin 500mg QDS (erythromycin/clarithro if allergic)
1. Safety-net re: spreading or systemic signs
1. Elevate limb
Inpatient:
1. Admit if: systemic symptoms, facial cellulitis, rapid progression
1. IV abx (e.g. flucloxacillin ± benzylpenicillin)
1. Rule out necrotising fasciitis if disproportionate pain/rapid progression
13
Q
Herpes simplex virus (HSV) features
A
- Painful grouped vesicles on erythematous base, may ulcerate
- Common on lips (HSV-1) or genitals (HSV-2)
- Swab for PCR/Viral culture if uncertain
- Primary episode: fever, malaise, lymphadenopathy
- Reactivation: recurrent cold sores or genital ulcers
- May cause eczema herpeticum if superimposed on eczema (emergency)
14
Q
HSV Mx
A
Primary Care:
1. Mild oral/labial: self-limiting, topical aciclovir 5% may help early
1. Genital/first episode: oral aciclovir 400mg TDS for 5 days
1. Give safety-netting for signs of bacterial superinfection or systemic illness
Specialist Dermatology/inpatient:
1. Eczema herpeticum: urgent referral – requires IV aciclovir
1. Severe, frequent recurrences: consider prophylactic oral antivirals
15
Q
VZV - chickenpox features
A
- Crops of vesicles → pustules → crusted lesions
- Fever, malaise, pruritus
- More severe in adults, immunocompromised, and pregnanc
16
Q
VZV (chicken pox) Mx
A
Primary Care:
- Supportive: antihistamines, calamine lotion, paracetamol
- Oral aciclovir within 24h of rash onset in adults/high risk patients
- Exclude from school until all lesions crusted
Inpatient:
- Immunocompromised/pregnant/neonatal: oral aciclovir
- Notify public health if outbreak in vulnerable setting
17
Q
Herpes zoster (Shingles) features
A
- Unilateral dermatomal painful vesicular rash
- Burning/tingling prodrome
- Post-herpetic neuralgia common in elderly
- Ophthalmic zoster (V1): can threaten sight (Hutchinson’s sign = tip of nose)
18
Q
Herpes zoster (Shingles) mx
A
Primary Care:
- Oral aciclovir 800mg 5x/day for 7 days (within 72h ideally)
- Analgesia ± amitriptyline for neuropathic pain
- Refer if eye involved, immunosuppressed, or widespread rash
Specialist/Inpatient:
- Ophthalmic involvement: urgent ophthalmology referral
- IV antivirals if severe or immunocompromised
19
Q
Viral warts feat + mx
A
- Rough, hyperkeratotic papules, often on hands and feet
- May be flat or filiform
- Spread via contact
mx:
1. Reassurance: often resolve within 2 years
1. Topical salicylic acid or cryotherapy if bothersome
20
Q
Molluscum contagiosum feat + mx
A
- Umbilicated, skin-coloured papules, often grouped
- Most common in children, sexually active adults, immunosuppressed
- May be itchy or inflamed when resolving
mx:
1. Reassurance: self-limiting over 6–18 months
1. consider topical agents (e.g. benzoyl peroxide, imiquimod) or cryo if persistent
21
Q
Dermatophytosis (Tinea) features
A
“ring worm”
- Annular, scaly plaques with central clearing
- May be itchy
- Locations: corporis (body), cruris (groin), pedis (feet), capitis (scalp), unguium (nails)
22
Q
Dermatophytosis (Tinea) mx
A
- Topical clotrimazole or terbinafine for localized skin
- Oral terbinafine or itraconazole for scalp/nails/extensive infection
- Antifungal shampoo for scalp (ketoconazole)
23
Q
Candidiasis
Candida albicans features + RF
A
- Moist, erythematous patches with satellite pustules
- Common in skin folds (intertrigo), mouth (thrush), genitals
- Risk factors: immunosuppression, diabetes, antibiotics
24
Q
Candidiasis
Invx + Mx
A
Investigations:
- Swabs or scrapings for microscopy/culture
- Oral candidiasis: check HIV, diabetes if unexplained
Management:
- Topical clotrimazole, miconazole, or nystatin
- Oral fluconazole if extensive/oral
- Keep area dry, manage underlying causes
25
Scabies feat + mx
1. Intensely itchy, worse at night
1. Burrows: thin grey lines on wrists, web spaces, genitals
1. Often affects family/contacts
mx:
1. Permethrin 5% cream over whole body, repeat in 7 days
1. Treat all close contacts simultaneously
1. Wash bedding/clothing at 60°C
1. May need oral ivermectin under specialist supervision
26
Head lice feat + mx
1. Itchy scalp
1. Lice visible
1. Can see with fine-tooth nit comb
mx:
1. Dimeticone lotion, wet combing
1. Repeat treatment after 7 days
1. Treat close contacts
27
Atopic dermatitis (eczema) features
1. Chronic itchy, inflamed skin (flexures in children)
1. Often family history of atopy
1. Dry skin, lichenification, flare-ups
28
Atopic dermatitis (eczema) - primary care Mx
1. Emollients: frequent use, including soap substitutes
1. Topical corticosteroids: lowest potency for shortest time needed
1. Mild: hydrocortisone 1%
1. Moderate: clobetasone butyrate (Eumovate)
1. Identify and avoid triggers (irritants, allergens)
1. Antihistamines for itch (esp. at night)
1. Treat infection if signs of impetiginisation (flucloxacillin, swab if MRSA likely)
29
Atopic dermatitis (eczema) - secondary care Mx
Topical anti-inflammatories:
1. calcineurin inhibitors (e.g. tacrolimus)
2. JAK inhibitors
physical therapies:
1. Phototherapy (ultraviolet B and PUVA)
Systemic treatments:
1. ciclosporin
2. methotrexate
3. biologic injections - dupilumab
4. oral JAK inhib - upadacitinib
30
Contact dermatitis features + mx
1. Itchy rash in contact with irritants/allergens
1. Irritant: exposed to an irritant at sufficient concentration for long enough, non-immune mediated
1. Allergic: individual allergen, even at low concentration. delayed hypersensitivity (type IV)
mx:
1. Avoid trigger
1. mild-mod topical steroid
1. Barrier creams
31
Acne vulgaris feat
1. Inflammatory skin condition affecting pilosebaceous units
1. Common in adolescents and young adults
1. Comedones (open = blackheads, closed = whiteheads)
1. Papules, pustules, nodules, cysts
1. Face, chest, back (seborrhoeic areas)
1. May cause post-inflammatory hyperpigmentation or scarring
1. Can impact mental health significantly
32
Acne vulgaris - mild/mod
mx
Primary Care Management:
First-line:
12 week course of one of:
* topical **adapalene** (retinoid) + topical **benzoyl peroxide**
* topical **tretinoin** (retinoid - more potent) + topical **clindamycin**
* topical **benzoyl peroxide** + topical **clindamycin**
33
Acne vulgaris - mod/severe
mx
12 week course of:
- topical **adapalene** (retinoid) + topical **benzoyl peroxide**
- topical **tretinoin** (retinoid - more potent) + topical **clindamycin**
- topical **adapalene** + topical **benzoyl peroxide** + **oral lymecycline/ doxycycline**
- topical **azelaic acid** + **oral lymecycline/doxycycline**
consider COCP in women
34
Acne vulagaris Mx considerations
DO NOT use:
- monotherapy with topical abx
- monotherapy with oral abx
- combination of topical + oral abx
- tetracycline - avoid in pregnant, breastfeeding or <12
- use erythromycin in pregnancy
- pregnancy contraindication to topical and oral retinoid
35
Acne vulgaris -
when to refer, secondary care Mx
when to refer:
- acne congloblate
- nodulo-cystic
- not responded to 2 courses of treatment or treatment with oral abx
- scarring
- pigmentary changes
- psychological distress
Severe nodulocystic acne or scarring: **oral isotretinoin** (requires specialist prescribing, contraception monitoring)
36
Psoriasis feat
1. Chronic, erythematous plaques with silvery scale
1. Extensor surfaces, scalp, umbilicus, sacrum
1. Assess severity (PASI score), DLQI
37
Psoriasis types
1. Chronic plaque psoriasis (most common): well-demarcated red plaques with silvery scale, often on extensor surfaces, scalp, sacrum
1. Guttate psoriasis: small drop-like lesions, often post-streptococcal infection
1. Flexural (inverse): shiny red plaques in skin folds with little/no scale
1. Pustular psoriasis: sterile pustules on palms/soles (localised) or widespread (emergency)
38
Other manifestations of psoriasis
1. Nail changes: pitting, onycholysis, subungual hyperkeratosis
1. Psoriatic arthritis in up to 30%: dactylitis, enthesitis, oligoarthritis
39
Psoriasis: metabolic syndrome
- obesity
- hypertension
- dyslipidaemia
- insulin resistance
40
Psoriasis mx
**Primary Care Management:**
1. smoking cessation, alcohol and diet advice
Topical therapy (first-line):
1. Emollients
1. Vitamin D analogues (calcipotriol, once/twice daily)
2. coal tar
3. salicylic acid
1. Topical corticosteroids (short courses; mild/moderate potency)
**Specialist Management:**
1. Phototherapy: Narrowband UVB for widespread/resistant disease
Systemic therapy:
1. Methotrexate (monitor FBC/LFTs)
1. Ciclosporin, acitretin
1. Biologics (e.g. adalimumab, secukinumab) for severe disease — screen for TB, hepatitis
Psoriatic arthritis → refer to rheumatology
41
Acute urticaria feat
1. Sudden, itchy, raised wheals lasting less than 24 hours each (new ones appear over days)
1. Blanch with pressure, often with swelling (angioedema)
1. Triggered by infection, allergens, insect bites, or idiopathic
1. No systemic illness signs (if present, think anaphylaxis or other)
42
Acute urticaria mx
1. Non-sedating antihistamines (e.g., cetirizine),
1. short course oral steroids if severe
1. Refer if symptoms persist >6 weeks (chronic urticaria)
43
Chronic urticaria feat
1. Recurrent itchy wheals and/or angioedema lasting >6 weeks
1. Lesions similar to acute urticaria but persist or recur frequently
1. Often idiopathic, can be autoimmune
1. No systemic symptoms usually
44
chronic urticaria mx
1. Primary care: Increase non-sedating antihistamines up to 4x standard dose
1. Specialist: If symptoms persist despite high-dose antihistamines, consider omalizumab or immunosuppressants
45
Erythema Multiforme feat
1. Acute, immune-mediated hypersensitivity reaction
1. Target lesions: concentric rings with central dusky area
1. Usually on extremities, sometimes mucosal involvement (mild)
1. Common triggers: infections (especially HSV), drugs
46
Erythema Multiforme mx
Primary care:
1. Supportive care,
1. treat underlying infection (e.g., antivirals for HSV)
Specialist:
1. Systemic corticosteroids in severe cases,
1. recurrent EM may require long-term antivirals
47
Steven- johnsons syndrome (SJS)/Toxic Epidermal necrolysis (TEN) feat
1. Severe mucocutaneous reaction, usually drug-induced
1. Painful red/purple skin, blistering, epidermal detachment (like burns)
1. Nikolsky’s sign positive (skin sloughs off with slight pressure)
1. Mucous membranes involved (mouth, eyes, genitals)
1. SJS under 10% body surface area, TEN >30% BSA
1. Systemic symptoms: fever, malaise, organ involvement
48
Steven- johnsons syndrome (SJS)/Toxic Epidermal necrolysis (TEN) mx
1. Urgent hospital admission, ideally burns or ICU unit
1. Stop offending drug immediately
1. Supportive care: fluids, wound care, pain management
1. Consider immunomodulatory treatments (IVIG, ciclosporin)
49
Eczema herpeticum feat
1. Acute, widespread vesicular eruption over areas of atopic eczema
1. Painful, punched-out erosions, sometimes with fever and malaise
1. Caused by herpes simplex virus infection (usually HSV-1)
1. Can spread rapidly and become severe if untreated
50
Eczema herpeticum mx
1. Urgent referral to hospital
1. Systemic antivirals (e.g., aciclovir),
1. supportive care,
1. manage eczema concurrently
51
Necrotising Fasciitis feat
1. Rapidly progressing infection of deep fascia and subcutaneous tissue
1. Severe pain out of proportion to skin findings
1. Swelling, erythema, blistering, skin necrosis
1. Systemic toxicity: fever, shock, organ failure
52
Necrotising fasciitis invx
1. Clinical diagnosis (emergency)
1. Blood tests: raised CRP, WCC, lactate
1. Imaging (CT or MRI) can help but should NOT delay treatment
1. Surgical exploration is definitive
53
Necrotising fasciitis mx
1. Emergency surgical debridement (specialist care)
1. Broad-spectrum IV antibiotics immediately
1. Supportive intensive care
54
Erythroderma feat
1. Generalised redness and scaling affecting >90% of body surface
1. May be due to eczema, psoriasis, drug reactions, or malignancy (e.g. CTCL)
1. Skin feels hot, dry, and itchy; may have oedema, lymphadenopathy
1. Systemic symptoms: fever, malaise, fluid/electrolyte imbalance
55
Erythroderma mx
1. Admit to hospital for monitoring and supportive care
1. Emollients, fluid balance, temperature regulation
1. Treat underlying cause (e.g., stop culprit drug, manage eczema/psoriasis)
1. Specialist dermatology involvement essential
56
Staphylococcal scalded skin syndrome (SSSS) feat
1. Caused by exfoliative toxins from Staph. aureus
1. Mainly affects infants and young children
1. Widespread painful erythema, blistering, and skin peeling
1. Nikolsky’s sign positive (skin sloughs off with gentle pressure)
1. No mucosal involvement (unlike SJS/TEN)
57
Staphylococcal scalded skin syndrome (SSSS) mx
1. Admit to hospital (paediatrics or burns unit)
1. IV antibiotics (e.g., flucloxacillin)
1. Supportive care: fluids, skin care, analgesia
1. Specialist dermatology or paediatric infectious diseases involvement
58
Bites and stings
feat + mx
Features:
1. Local pain, swelling, urticaria
1. Infection (cellulitis) or allergic reaction possible
1. Watch for anaphylaxis (esp. bee/wasp stings)
1. Tick bites → Lyme disease (erythema migrans)
Management:
1. Mild: cold compress, antihistamines, analgesia
1. Infected: flucloxacillin
1. Anaphylaxis: IM adrenaline, emergency referral
1. Lyme suspicion: doxycycline if erythema migrans
59
Burns feat
Classified by depth:
1. Superficial (1st degree): red, painful, no blister
1. Partial thickness (2nd degree): blistered, painful
1. Full thickness (3rd degree): white/charred, painless
1. Assess % Total Body Surface Area (TBSA) burned
1. Watch for signs of airway involvement, shock
60
Burns mx
1. Cool burn (cool water ≤20 mins), analgesia
1. Cover with cling film (not cotton), keep warm
Refer to burns unit if:
1. 10% TBSA, full thickness, face/hands/genitals
1. Inhalation injury, chemical/electrical burns
1. Fluids if >15% TBSA in adults (Parkland formula)
61
Actinic Keratosis feat
1. Rough, scaly patches on sun-exposed areas (face, scalp, forearms, backs of hands)
1. May be pink, red, or skin-coloured
1. Common in older, fair-skinned individuals with long-term sun exposure
1. Premalignant: small risk (~1%) of progressing to squamous cell carcinoma (SCC)
1. Biopsy if lesion is atypical, thickened, ulcerated, or rapidly changing
62
Actinic Keratosis mx
1. Sun protection advice
1. Emollients ± topical treatments:
1. 5-fluorouracil (Efudix)
1. Imiquimod
1. Diclofenac gel
1. Cryotherapy for isolated lesions
63
Bowen's disease features
1. Well-demarcated, scaly, red plaque
1. Often on sun-exposed skin (e.g., lower legs in elderly women)
1. Slowly enlarging, may mimic psoriasis or eczema
1. Premalignant: ~3–5% risk of progression to invasive SCC
64
Bowen's disease mx
1. Sun protection
1. Topical 5-fluorouracil or imiquimod
1. Cryotherapy
1. Excision if high-risk site or non-responsive
65
BCC feat
1. Most common skin cancer
1. Pearly, translucent nodule with telangiectasia
1. May ulcerate (“rodent ulcer”)
1. Slow-growing, locally invasive, rarely metastasises
1. Typically on sun-exposed areas (face, neck)
66
BCC mx
1. Routine dermatology referral
1. Surgical excision (first-line) with 4mm margin
1. Mohs micrographic surgery for high-risk or facial lesions
1. Alternative: curettage + cautery, cryotherapy, topical imiquimod or 5-FU for superficial BCCs
67
SCC feat
1. Firm, scaly or crusted nodule or plaque
1. May ulcerate or bleed; often tender
1. Arises on sun-exposed skin or sites of chronic inflammation (e.g., ulcers, scars)
1. Can metastasise (unlike BCC) — especially high-risk lesions
68
SCC mx
1. Urgent skin biopsy or excision (2WW/FDS referral)
1. Surgical excision with ≥4 mm margin (≥6 mm for high-risk SCC)
1. Consider wider excision or lymph node assessment if invasive
1. Radiotherapy if surgery not possible
1. Follow-up for high-risk lesions due to recurrence/metastasis risk
69
Benign melanocytic naevi (moles)
1. Symmetrical, smooth-edged pigmented lesions
1. Even colour, < 6 mm diameter
1. May be flat or raised
1. Can darken or enlarge during adolescence, pregnancy
1. Monitor for changes using ABCDE rule
70
Malignant Melanoma feat
**Irregular pigmented lesion** — assess with ABCDE:
1. Asymmetry
1. Border irregularity
1. Colour variation
1. Diameter >6 mm
1. Evolving (change in size/shape/colour)
1. May bleed, itch, or ulcerate
71
Malignant melanoma invx
1. Urgent excisional biopsy with 2 mm margin (never shave/punch)
1. Histology: subtype + Breslow thickness (guides prognosis)
1. Staging: sentinel lymph node biopsy, imaging if invasive
72
Malignant melanoma mx
1. Urgent 2WW referral if melanoma suspected
1. Wide local excision based on Breslow thickness
1. Consider lymph node mapping, immunotherapy for advanced disease
1. Long-term follow-up (risk of recurrence and second melanoma)
73
Seborrhoeic Keratosis feat
1. Common benign epidermal tumour, usually in older adults
1. Well-demarcated, “stuck-on” appearance
1. Variable colour: tan, brown, black
1. Rough, warty surface, can be slightly raised or flat
1. Usually multiple, on trunk, face, neck
74
Seborrhoeic Keratosis mx
1. Usually none needed (benign, asymptomatic)
1. Removal for cosmetic reasons or if irritated: cryotherapy, curettage, laser, or excision
75
Seborrhoeic Dermatitis feat
1. Chronic inflammatory condition affecting seborrhoeic (oil-rich) areas: scalp, face (especially nasolabial folds), eyebrows, chest
1. Red, flaky, greasy-scaly patches with mild itch
1. Often worse in winter or stress
1. Can overlap with dandruff (scalp variant)
1. Common in infants (cradle cap) and adults
76
Seborrhoeic Dermatitis Mx
| Primary care + dermatologist
Primary care:
1. Antifungal shampoos (e.g., ketoconazole),
1. mild topical corticosteroids for flare-ups,
1. emollients
Dermatologist:
1. Stronger topical corticosteroids,
1. topical calcineurin inhibitors (e.g., tacrolimus),
1. consider antifungal oral therapy in resistant cases
77
Dermatitis Herpetiformis feat
1. Chronic, intensely itchy, symmetrical vesicular rash
1. Common sites: elbows, knees, buttocks, scalp, back
1. Small grouped vesicles and papules, often excoriated
1. Associated with gluten-sensitive enteropathy (coeliac disease)
1. May have gastrointestinal symptoms or be asymptomatic
78
Dermatitis Herpetiformis invx
1. Skin biopsy with direct immunofluorescence: granular IgA deposits at dermal-epidermal junction (pathognomonic)
1. Serology: anti-tissue transglutaminase (tTG) antibodies
1. Consider small bowel biopsy for coeliac confirmation
79
Dermatitis Herpetiformis mx
| Primary care + dermatologist
Primary care:
1. Support diagnosis,
1. start gluten-free diet (coordination with dietitian)
Specialist:
1. Dapsone to rapidly control symptoms (requires G6PD testing before)
Long-term management:
1. strict gluten-free diet for remission and to prevent complications
80
Rosacea feat
1. Chronic inflammatory facial skin condition
1. Central facial redness (erythema), flushing, telangiectasia
1. Papules and pustules, usually no comedones (helps distinguish from acne)
1. Commonly affects cheeks, nose, forehead, chin
1. May have ocular involvement (dry, irritated eyes)
81
Rosacea triggers
1. sun exposure,
1. heat,
1. alcohol,
1. spicy food,
1. stress
82
Rosacea mx
| Primary care + specialist
Primary care:
1. Avoid triggers,
1. gentle skin care,
1. topical metronidazole or azelaic acid
Specialist:
1. Oral antibiotics (e.g., doxycycline) for inflammatory lesions,
1. laser therapy for telangiectasia,
1. management of ocular rosacea with ophthalmology input
