TO DO DERMATOLOGY Flashcards
ACNE VULGARIS
Briefly describe the pathophysiology of acne
comedones are non-inflammatory lesions and can be open (blackheads) or closed (whiteheads). When the follicle bursts, inflammatory lesions such as papules and pustules may form. Excessive inflammation results in nodules, and cysts
ACNE VULGARIS
Describe the signs of acne
MILD
- non-inflamed lesions (open + closed comedones) with few inflammatory lesions
MODERATE
- more widespread
- increased inflammatory papules + pustules
SEVERE
- widespread inflammatory papules pustules, nodules or cysts
- scarring
ACNE VULGARIS
Describe the treatment for acne
1st line
- topical retinoid +/- benzoyl peroxide,
- topical antibiotic (clindamycin)
- topical azelaic acid 20%
2nd line
- oral tetracycline (doxycycline, lymecycline) with topical benzoyl peroxide +/- topical retinoid
- COCP (co-cyprindiol)
3rd line
- isotretinoin (accutane)
ECZEMA
what is the management?
MILD
- emollients
- mild corticosteroids (hydrocortisone 1%)
MODERATE
- emollients
- moderate corticosteroids (betamethasone 0.025% or clobetasone 0.05%)
- antihistamines
SEVERE
- emollients
- potent corticosteroid (betamethasone 0.1%)
- oral corticosteroid
- antihistamine
BCC
what are the risk factors for BCC?
- male
- UV exposure
- fair skin
- xeroderma pigmentosa
- immunosuppression
- arsenic exposure
BCC
what is the clinical presentation?
- pearly indurated flesh-coloured papule with rolled border
- covered in telangiectasia
- may ulcerate + create central crater
CELLULITIS
what are the most common causes?
- s.aureus
- s.pyogenes
CELLULITIS
what are the risk factors?
- break in cutaneous barrier
- immunocompromise
- other skin conditions (eczema, shingles)
- history of cellulitis
- obesity
- venous insufficiency
- lymphoedema
CELLULITIS
how is it classified?
Erons classification
CLASS 1 - no systemic signs (outpatient/oral abx)
CLASS 2 - systemically unwell or systemically well but have comorbidity (possible admission)
CLASS 3 - significant systemic upset (admission required)
CLASS 4 - sepsis
CELLULITIS
what is the management?
antibiotics
- 1st line = flucloxacillin
- if penicillin allergic = clarthromycin/erythromycin/doxycycline
- 1st line if near eyes/nose = co-amoxiclav
- severe infection = co-amoxiclav/cefuroxime/clindamycin
- MRSA = add vancomycin
CONTACT DERMATITIS
give some examples of common allergens that cause contact dermatitis
nickel sulfate
neomycin
formaldehyde
sodium gold thiosulfate
CONTACT DERMATITIS
what are the risk factors?
- occupation with frequent exposure to water and caustic materials e.g. labourers, chefs, farmers
- history of atopic eczema
CONTACT DERMATITIS
how long do symptoms last for?
- ICD takes 3-6 weeks to resolve
- ACD typically resolves within a few days
CONTACT DERMATITIS
what is the management for irritant contact dermatitis (ICD)?
1st line
- avoidance of irritant
- skin emollients
2nd line
- topical corticosteroids (hydrocortisone, betamethasone)
CONTACT DERMATITIS
what is the management of allergic contact dermatitis (ACD)?
1st line
- avoidance of allergen
- topical corticosteroids (hydrocortisone, betamethasone)
2nd line
- topical calcineurin inhibitors (tacrolimus, pimecrolimus)
3rd line
- oral corticosteroids (prednisolone, dexamethasone)
- phototherapy (BUVB, PUVA)
- immunosuppressants (azathioprine, ciclosporin)
CUTANEOUS WARTS
what is the pathophysiology?
they are caused by human papillomavirus (HPV) types 2 and 4
The virus invades the skin through small cuts or abrasions and causes rapid growth of cells on the outer layer of the skin, leading to the formation of a wart
CUTANEOUS WARTS
what are the risk factors?
- use of public showers
- close contact with a person with warts
- skin trauma
- immunosuppression
- meat handlers
- Caucasian ethnicity
CUTANEOUS WARTS
what are the clinical features?
often asymptomatic
- firm rough papules or nodules
- interrupted skin lines over warts
- black dots within wart (thrombosed capillaries)
CUTANEOUS WARTS
what is the management?
1st line
- watchful waiting
- topical salicylic acid
2nd line
- cryotherapy (freezing with liquid nitrogen)
- immunotherapy
FOLLICULITIS
what are the risk factors?
- trauma (shaving, hair extraction)
- topical corticosteroid use
- diabetes mellitus
- immunosuppression
- drug-induced (corticosteroids, androgenic hormones, isoniazid, lithium)
- hot tub use
chronic inflammatory skin disease
FOLLICULITIS
what is hot tub folliculitis caused by?
pseudomonas aeruginosa
FOLLICULITIS
what are the clinical features?
SYMPTOMS
- erythema
- papules (small, clusters)
- pustules (small, whiteheads)
- pruritis (localised)
SIGNS
- localised to shaving area
- blistering if severe
- subdermal mass (abscess if severe)
- raised eosinophils
FOLLICULITIS
what is the management?
CONSERVATIVE
- use clean sterile razors for shaving
- wear loose clothing
- antibacterial soap
- avoid hot tubs
MEDICAL
- mild = no treatment or topical antibiotics
- moderate bacterial = oral flucloxacillin (s.aureus) or oral ciprofloxacin (pseudomonas)
- moderate viral = oral aciclovir
- moderate fungal = ketoconazole, fluconazole, itraconazole
CUTANEOUS FUNGAL INFECTION (RINGWORM)
what are the risk factors?
- close contact with infected individuals or animals
- damp, warm environments
- participation in contact sports
- shared facilities
- immunocompromised states
CUTANEOUS FUNGAL INFECTION (RINGWORM)
what are the clinical features?
SYMPTOMS
- itching
- discomfort
- hair loss
SIGNS
- annular (ring shaped lesions)
- central clearing of the rash
- scaling of the skin
- erythema
- nail thickening and crumbling
CUTANEOUS FUNGAL INFECTION (RINGWORM)
what is the management?
1st line
- topical antifungals (clomitrazole, terbinafine)
- skin care (avoid sharing towels, keep area clean and dry)
2nd line
- oral antifungals (terbinafine, itraconazole, fluconazole)
HEAD LICE
what causes head lice?
parasites (Pediculus humanus capitis) cause an infestation called pediculosis capitis
HEAD LICE
what is the management?
1st line
- medicated lotions/sprays (dimeticone, isopropyl myrisate, cyclomethicone)
- wet combing (over 2 week period, days 1, 5, 9 and 13)
- insecticide (malathion)
IMPETIGO
what are the most common causative organisms?
s.aureus = most common
s.pyogenes
IMPETIGO
what is the management?
non-bullous
- localised = hydrogen peroxide 1% cream or topical antibiotic (fusidic acid, mupirocin)
- widespread = topical (fusidic acid or mupirocin) or oral antibiotics (flucloxacillin, clarithromycin or erythromycin)
bullous
- oral antibiotics (flucloxacillin, clarithromycin or erythromycin)
IMPETIGO
what is the general advice for school/work?
- avoid sharing towels
- stay away until lesions have healed, dry and crusted over or 48 hours after initiation of antibiotics
LICHEN PLANUS
what is the pathophysiology?
immune response leading to T-cell mediated inflammation and keratinocyte apoptosis
LICHEN PLANUS
what are the risk factors?
- ages 40-60
- hep C
- drugs (thiazide diuretics, beta-blockers, NSAIDS and antimalarials)
- vaccinations
- stress
- family history
LICHEN PLANUS
what are the clinical features?
SYMPTOMS
- itching
- oral discomfort
- hair loss
SIGNS
- purple, polygonal, flat-topped papules on wrists, ankles and lower back
- wickhams striae (white streaks overlying rash)
- rough thinning nails with grooves
- sore, red patches on vulva
- ring-shaped (annular) purple/white patches on penis
LICHEN PLANUS
what is the management?
1st line
- topical corticosteroids
- conservative (wash with warm water, emollients, avoid tight clothing)
2nd line
- oral corticosteroids
- topical calcineurin inhibitors (tacrolimus)
- phototherapy
MALIGNANT MELANOMA
why can it affect GI tract and brain?
melanocytes are derived from neural crests
melanoma can occur anywhere neural cells migrate such as GI tract and brain
MALIGNANT MELANOMA
what is the most common gene mutation associated with melanomas?
BRAF gene mutation - found in 50% of cases
MALIGNANT MELANOMA
what are the risk factors?
- increasing age
- family history
- pale skin (fitzpatrick type I and II)
- red/blonde/light coloured hair
- UV exposure
- precursor lesions (dysplastic naevi)
- previous skin cancer
- immunosuppression
- xeroderma pigementosum
MALIGNANT MELANOMA
how do you assess a nevus?
ABCDE
A - asymmetry of lesion
B - border irregular
C - colour non-uniform
D - diameter >6 mm
E - evolution: changing shape, size or colour
MALIGNANT MELANOMA
what are the different types?
- superficial spreading (most common, horizontal growth)
- nodular (may ulcerate + bleed, vertical growth)
- lentigo maligna (seen in elderly, on face)
- acral lentiginous (palms, soles and nailbed, more common in darker skin)
- amelanotic (pink, lack pigment)
MALIGNANT MELANOMA
what is the diagnostic criteria?
MAJOR (2 points each)
- change in size
- irregular shape/border
- irregular colour
MINOR (1 point each)
- largest diameter >7mm
- inflammation
- oozing or crusting
- change in sensation (including itch)
> 3 points = strong concerns about cancer
MALIGNANT MELANOMA
what are the investigations?
- dermoscopy (ABCDE)
- excision biopsy
to consider
- sentinel node biopsy
- CT chest, abdomen and pelvis
- genetic studies
MALIGNANT MELANOMA
how is it staged?
AJCC staging system
0 = confined to epidermis, melanoma in situ
1 = breslow thickness <2mm, no nodal involvement/mets
2 = breslow thickness 1-2mm with ulceration, or >2mm with/without ulceration, no nodal involvement/mets
3 = any thickness, involvement of local skin/LN
4 = any thickness, distant mets/LN
MALIGNANT MELANOMA
what is the management?
EARLY STAGE (0-2)
- excision with adequate margin
- topical imiquimod
STAGE 3
- LN dissection
- radiotherapy
- resection of mets
STAGE 4
- systemic treatments (chemo/immunotherapy)
- radiotherapy
- resection of mets
MALIGNANT MELANOMA
where does it tend to spread to?
lymph nodes
brain
bones
liver
lung
GI tract
PITYRIASIS ROSEA
what is it?
inflammatory skin condition of uncertain aetiology, though an association with human herpesviruses 6 and 7
PITYRIASIS ROSEA
what is the characteristic feature?
herald patch - single, oval scaly patch up to 10cm diameter and appears 2 weeks before rest of rash
PITYRIASIS ROSEA
what are the clinical features?
- herald patch
- itchy rash (erythematous, oval, papular scaly patches on trunk + extremities)
- fir tree appearance
PITYRIASIS ROSEA
what is the management?
- emollients
- topical steroid = mild (hydrocortisone 1%) or moderate (betamethasone valerate 0.025%)
- antihistamine (chlorphenamine) if itching affects sleep
PITYRIASIS VERSICOLOR
what is it?
common superficial fungal infection caused by the Malassezia species, a yeast that is part of the normal skin flora
PITYRIASIS VERSICOLOR
what are the risk factors?
- hot and humid climates
- excessive sweating
- oily skin
- immunocompromised
- age (teenagers + young adults)
PITYRIASIS VERSICOLOR
what are the clinical features?
- itching (may also be asymptomatic)
- rash on back, chest and upper arms
- well-demarcated round/oval scaly patches
- rash worsens with sun exposure
- colour variation
PITYRIASIS VERSICOLOR
what is the management?
1st line
- topical antifungals (ketonazole, selenium sulphide shampoo)
- sun protection
2nd line
- oral antifungals (fluconazole)
PSORIASIS
what is the pathophysiology?
- immune-mediated
- abnormal T-cell activity that stimulates proliferation of keratinocytes
PSORIASIS
what are the genetic factors that are strongly associated with psoriasis?
HLA-B13
HLA-B17
PSORIASIS
what are the risk factors?
- family history
- obesity
- smoking and alcohol consumption
- medications (ACEi, BB, NSAIDs, lithium, hydroxychloroquine, steroid withdrawal, abx)
PSORIASIS
what are the nail changes?
- pitting
- onycholysis
- subungual hyperkeratosis
- nail loss
PSORIASIS
what is the management?
1st line
- patient education
- regular emollients
- topical corticosteroids + vit D for 4 weeks
- if poor response, continue for 4 more weeks
- if poor response after 8 weeks, stop corticosteroid + take vit D BD
- if poor response after 12 weeks, potent topical steroid BD for 4 weeks
2nd line
- short-acting dithranol
- phototherapy
3rd line
- DMARDS (methotrexate, apremilast, ciclosporin)
- biologics (adalimumab, infliximab)
SCABIES
what is the pathophysiology?
- infestation with Sarcoptes scabiei
- type IV hypersensitivity reaction
SCABIES
how long does it take for symptoms to develop?
- 1st time exposure = 3-6 weeks
- it is contagious before the rash develops
- in cases of re-infestation = 1-3 days
SCABIES
what is the management?
1st line
- permethrin 5% cream
- topical crotamiton cream (symptomatic relief)
2nd line
- malathion aqueous 0.5%
SCC
what is the pre-cancerous form of SCC?
actinic keratosis
SCC
what are the invasive forms of SCC?
- cutaneous horn
- marjolin ulcer
- keratoacanthoma
SCC
what are the risk factors?
- sun exposure and history of sunburns
- use of tanning beds
- chronic skin inflammation or injury
- HPV infection
- immunosuppression
SCC
what are the clinical features?
SYMPTOMS
- itchy, tender or painful lesions
- ulcerating lesions
- lesions on sun-exposed areas
SIGNS
- scaly or erythematous lesions
- crusted or indurated lesions
- bleeding lesions
- irregular borders
SCC
what is the management?
- surgical excision (wide local or Mohs)
- agressive cryotherapy
- topical 5-fluorouracil
- imiquimod
- radiotherapy
NECROTISING FASCIITIS
what are the different types?
it is classified according to causative organism
type 1 = polymicrobial (most common)
type 2 = group A haemolytic strep (s.pyogenes)
type 3 = gas gangrene
type 4 = fungal
NECROTISING FASCIITIS
what are the risk factors?
- recent trauma, burns or skin infection
- increasing age
- immunosuppressed
- DM
- SGLT-2 inhibitors
- marine exposure
- close contact with someone with necrotising fasciitis
NECROTISING FASCIITIS
what are the clinical features?
EARLY
- intense pain
- skin puncture or injury
- flu-like symptoms
- erythema, warmness, swelling, tenderness
- hypersensitive site
- fever
LATE
- gas or crepitus
- skin necrosis
- fever
- purple/blue skin discolouration
- reduced sensation
- hypotension + tachycardia
NECROTISING FASCIITIS
what is the management?
- immediate surgical debridement
- IV antibiotics (broad-spectrum)
- supportive care
- amputation
URTICARIA AND ANGIOEDEMA
what are the causes?
- viral infection
- idiopathic
- cold
- heat
- exercise
- stress
- medications - NSAIDS, antihypertensives
- thyroid function
URTICARIA AND ANGIOEDEMA
what is the management?
- 1st line = non-sedating antihistamines (cetirizine, loratadine and fexofenadine)
- 2nd line = leukotriene receptor antagonists - montelukast, or omalizumab
if symptoms persist a short course of oral corticosteroid can be used in addition to above
SYMPTOMATIC RELIEF
- calamine lotion
- topical menthol 1% aqueous cream
- sedating antihistamines (chlorphenamine) if disturbing sleep
GANGRENE
what are the different types?
wet gangrene = infectious gangrene (necrotising fasciitis, gas gangrene)
dry gangrene = ischaemic gangrene secondary to reduced blood flow
GANGRENE
what are the causes of dry gangrene?
atherosclerosis
peripheral artery disease
thrombosis
vasculitis
vasospasm
GANGRENE
what are the clinical features of dry gangrene?
well-demarcated necrotic area without signs of infection
GANGRENE
what are the clinical features of wet gangrene?
necrotic area is poorly demarcated from surrounding tissue
patients present with fever + sepsis
GANGRENE
what are the investigations for wet gangrene?
BLOODS
- FBC
- blood cultures
- inflammatory markers (CRP + ESR)
IMAGING
- X-ray, USS or CT scan (to assess extent of disease)
TISSUE BIOPSY
- to identify causative organism
GANGRENE
what are the investigations for dry gangrene?
BLOODS
- FBC
- inflammatory markers (CRP + ESR)
- glucose level
- coagulation profile
IMAGING
- doppler USS or angiography
TISSUE BIOPSY
- not typically needed
GANGRENE
what is the management of wet gangrene?
- surgical debridement
- amputation
- broad-spectrum antibiotics
GANGRENE
what is the management of dry gangrene?
- surgical debridement
- amputation
GANGRENE
what is the cause of gas gangrene?
clostridium perfringens
GANGRENE
what are the clinical features of gas gangrene?
- acute onset severe localised pain
- minimal local inflammation
- skin darkening + spreading erythema
- fever (hot to touch)
- gas production in affected area
- distinctive potent smell from infected area
URTICARIA AND ANGIOEDEMA
what are the risk factors?
- allergens (food, medications, insect stings)
- physical stimuli (pressure, cold, heat)
- infections (viral, bacterial)
- autoimmune processes
- stress + emotional factors
ONYCHOMYCOSIS
what are the causative organisms?
- dermatophytes (trichophyton rubrum) = most common
- yeasts (candida)
- non-dermatophyte moulds
ONYCHOMYCOSIS
what are the risk factors?
- increasing age
- diabetes mellitus
- psoriasis
- repeated nail trauma
ONYCHOMYCOSIS
what is the management?
- asymptomatic = not treatment
limited involvement (<50% nail affected, <2 nails affected, superficial)
- 1st line = topical amorolfine 5% nail lacquer, 6m for hands + 9-12m for feet
extensive dermatophyte infection
- 1st line = oral terbinafine, 6w-3m for hands + 3-6m for feet
extensive candida infection
- 1st line = oral itraconazole, ‘pulsed’ weekly therapy
ROSACEA
what are the clinical features?
- typically affects nose, cheeks + forehead
- flushing is often 1st symptom
- telangiectasia
- later develops into persistent erythema with papules + pustules
- rhinophyma
- ocular involvement (blepharitis)
- sunlight may exacerbate symptoms
ROSACEA
what is the management?
CONSERVATIVE
- high factor sun cream
- camouflage cream to conceal redness
SYMPTOM CONTROL
- flushing = topical brimonidine gel or oral propranolol
- telangiectasia = laser therapy
- papules/pustules
- mild-moderate = 1st line - ivermectin (other options = topical metronidazole, topical azelaic acid)
- mod-severe = topical ivermectin + oral doxycycline
