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 mild to moderate acne
12 week fixed course of one of the following:
- topical adapalene + topical benzoyl peroxide
- topical tretinoin + topical clindamycin
- topical benzoyl peroxide + topical clindamycin
ACNE
what is the management of moderate to severe acne?
1st line = 12 week fixed course of one of the following:
- topical adapalene + topical benzoyl peroxide
- topical tretinoin + topical clindamycin
- topical adapalene + topical benzyl peroxide + oral lymecycline/doxycycline
- topical azelaic acid + oral lymecycline/doxycycline
2nd line = isotretinoin (acutane)
ACNE
what is a complication of long term antibiotic use in acne treatment? How is this managed?
- gram negative folliculitis
- managed with high dose trimethoprim
ACNE
what can be used as an alternative to oral antibiotics in acne treatment in women?
COCP
ACNE
what is the risk of using co-cyprindiol to manage acne?
increased VTE risk so used 2nd line and only used for 3 months
ACNE
how does acne management change in pregnancy?
- topical and oral retinoids are contraindicated
- oral erythromycin is used instead of lymecycline or doxycycline in pregnant and breastfeeding
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
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
CONTACT DERMATITIS
give some examples of common allergens that cause contact dermatitis
nickel sulfate
neomycin
formaldehyde
sodium gold thiosulfate
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 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 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 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?
only treat if living lice are found
1st line:
- medicated lotions/sprays (dimeticone, isopropyl myrisate, cyclomethicone)
- wet combing (over 2 week period, days 1, 5, 9 and 13)
- insecticide (malathion)
HEAD LICE
how should you manage household contacts?
only need to be treated if they are also affected and found to have living lice
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)
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
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
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 management?
- emollients
- topical steroid = mild (hydrocortisone 1%) or moderate (betamethasone valerate 0.025%)
- antihistamine (chlorphenamine) if itching affects sleep
PITYRIASIS VERSICOLOR
what are the risk factors?
- hot and humid climates
- excessive sweating
- oily skin
- immunocompromised
- age (teenagers + young adults)
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
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
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 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 is the cause of gas gangrene?
clostridium perfringens
ONYCHOMYCOSIS
what are the causative organisms?
- dermatophytes (trichophyton rubrum) = most common
- yeasts (candida)
- non-dermatophyte moulds
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
