Derm Flashcards
causes of acanthosis nigricans
- T2DM
- gastrointestinal cancer
- obesity
- PCOS
- acromegaly
- Cushing’s disease
- hypothyroidism
- familial
- Prader-Willi syndrome
- drugs
- COCP
- nicotinic acid
name for whiteheads and blackheads
W- closed comedones
B- open comedones
categories of acne
- Mild: open/closed comedones +/-sparse inflammatory lesions
- Moderate: widespread non-inflammatory lesions and numerous papules and pustules
- severe: extensive inflammatory lesions, which may include nodules, pitting, and scarring
Mx of mild acne
Mild: 12 weeks topical combination therapy:
- topical adapalene with topical benzoyl peroxide
- topical tretinoin with topical clindamycin
- topical benzoyl peroxide with topical clindamycin
- topical benzoyl peroxide may be used as monotherapy if these options are contraindicated or the person wishes to avoid using a topical retinoid or an antibiotic
Mx of moderate to severe acne
12-week course of one of the following options:
- topical adapalene with topical benzoyl peroxide
- topical tretinoin with topical clindamycin
- topical adapalene with topical benzoyl peroxide + either oral lymecycline or oral doxycycline
- a topical azelaic acid + either oral lymecycline or oral doxycycline
can use COCP instead of abx in females
when to refer acne to a dermatologist
- acne conglobate acne
- nodulocystic acne
- mild acne hasn’t responded to 2 trials of meds
- oral abx has not cleared it
- scarring or pigment changes
- psychological distress
Condition associated with coeliac disease
dermatitis herpetiformis
What is dermatitis herpetiformis
autoimmune blistering skin disorder due to IgA deposition
itchy, vesicular skin lesions on the extensor surfaces
Mx gluten free anad dapsone
what are salmon patches
- Vascular birthmark in half of newborn babies (stork marks/bites)
- pink and blotchy on forehead, neck, eyelids
- fade over a few months, though marks on the neck may persist
Psoriasis and subtypes
- red, scaly patches
- plaque psoriasis: MC! well-demarcated red, scaly patches affecting the extensor surfaces, sacrum and scalp
- flexural psoriasis: skin is smooth
- guttate psoriasis: transient psoriatic rash triggered by a streptococcal infection. Multiple red, teardrop lesions appear on the body
- pustular psoriasis: on palms and soles
what exacerbates psoriasis
- trauma
- alcohol
- drugs: beta blockers, lithium, antimalarials (chloroquine and hydroxychloroquine), NSAIDs and ACE inhibitors, infliximab
- withdrawal of systemic steroids
Mx of psoriasis
- emollients
- a potent corticosteroid applied once daily plus vitamin D analogue applied once daily for 4 weeks
Mx of guttate psoriasis
- most resolve in 2-3 months
- can use psoriasis topical agents
- UVB phototherapy if necessary
what is pityriasis rosea
- acute, self-limiting rash which tends to affect young adults
- recent viral infection
- herald patch then erythematous, oval, scaly patches in a characteristic distribution with the longitudinal diameters of the oval lesions running parallel to the line of Langer.
- Has an ‘xmas tree’ appearance
- Mx self-limiting 6-12 weeks
tinea capitis
- fungal infection
- flaky skin, itch, and hair loss
- kerion= raised, pustular, boggy masses which appear as numerous bright yellow areas with the skin surface surrounded by regions of hair loss and flakiness
- Mx- antifungal
seborrhoeic dermatitis
- fungus called Malassezia furfur
- eczematous lesions on the sebum-rich areas: scalp, periorbital, auricular and nasolabial folds
- otitis externa and blepharitis may develop
- associated with HIV and parkinson’s
- ketoconazole cream or 2% shampoo
Rosacea features and mx
- affects nose, cheeks and forehead
- flushing (first), telangiectasia, persistent erythema with papules and pustules, rhinophyma
- ocular involvement: blepharitis
- sunlight, exercise, alcohol may exacerbate symptoms
- Mx= suncream. Mild= topical brimonidine gel. Moderate= topical ivermectin. Severe= mod + oral doxycycline
complication of acne rosacea
rhinophyma (mx is to remove)
Toxic epidermal necrolysis (TEN)
life-threatening skin disorder that is most commonly seen secondary to a drug reaction
Drugs known to induce TEN
- phenytoin
- sulphonamides
- allopurinol
- penicillins
- carbamazepine
- NSAIDs
Mx- stop drug, supportive, IVIG
Actinic keratosis
- pre malignant due to chronic sun exposure
- small, crusty, scaly, lesions, well demarcated, pink/red/brown/same colour as skin
- Mx: 2/3 wks fluorouracil cream, topical imiquimod, cryotherapy, curettage and cautery
Athlete’s foot (tinea pedis)
- scaling, flaking, and itching between the toes
- topical imidazole, undecenoate, or terbinafine
Fungal nail infection causative organisms
- dermatophytes (90%): mainly Trichophyton rubrum
- yeasts (5-10%) e.g. Candida
- non-dermatophyte moulds
Ix for fungal nail infection
- nail clippings +/- scrapings
Mx of mild fungal nail infection
Less than 50% nail effected or 2 or < nails effected
- topical treatment with amorolfine 5% nail lacquer; 6 months for fingernails and 9 - 12 months for toenails
Mx of more severe fungal infection
dermatophyte
- oral terbinafine 6 weeks - 3 months for fingernail + 3 - 6 months for toes
candida
- oral itraconazole
seborrhoeic keratosis
- benign epidermal skin lesions in elderly
- stuck on appearance
- colour from flesh to light-brown to black
- keratotic plugs may be seen on the surface
- Mx: reasurre, can remove by curettage, cryo or shave biopsy
Pityriasis versicolor
- Malassezia furfur
- scale, pruritis, patches may be hypopigmented, pink or brown (hence versicolor). May be more noticeable following a suntan
- ketoconazole shampoo
Lichen planus mx
potent topical steroids
erysipelas
- localised skin infection caused by Streptococcus pyogenes
- Mx flucloxacillin
Scabies
- burrows into the skin, laying its eggs in the stratum corneum
- pruritis, burrows in fingers
- Mx: permerthrin for child and household 2 doses one week apart
Four D’s of pellagra (vitamin B3 deficiency)
Diarrhoea
Dermatitis
Dementia
Death
Periorificial dermatitis
- women aged 20-45 years old
- clustered erythematous papules, papulovesicles and papulopustules
most commonly in the perioral region but also the perinasal and periocular region - skin immediately adjacent to the vermilion border of the lip is spared
- Mx: steroids may worsen sx, treat with topical or oral antibiotics
Sebaceous cysts
- most common scalp, ears, back, face, and upper arm
- contain a punctum
- excise to prevent recurrence
dermatofibroma
- solitary firm papule or nodule around 5-10mm in size
- typically on a limb
- overlying skin dimples on pinching the lesion
- precipitated by injury i.e. insect bite
impetigo
- Staphy aureus or Strep pyogenes
- ‘golden’, crusted skin lesions typically found around the mouth, very contagious
- Mx: hydrogen peroxide 1% cream
- exclude from school until lesions are crusted and healed or 48 hours after commencing abx
Vitiligo
- well-demarcated patches of depigmented skin
- peripheries most affected
- trauma may precipitate new lesions (Koebner phenomenon)
- Mx: suncream, camouflage make-up, topical corticosteroids may reverse the changes if applied early, phototherapy
isotretinoin side effects
- dry skin (MC)
- teratogenic
- low mood
- raised triglycerides
- hair thinning
- nose bleeds
- intracranial hypertension
- photosensitivity
Types of melanoma
- superficial spreading (MC)
- nodular
- lentigo maligna
- acral lentiginous
superficial spreading melanoma features
- 70% cases
- arms, legs, back, chest, young
- irregular borders with variation in
colour, growing
nodular melanoma features
- second commonest
- sun exposed skin, middle aged
- Red or black lump or lump which bleeds or oozes
- can occur on all sites
- most aggressive, metastasis early
lentigo maligna melanoma features
- less common
- chronically sun exposed, elderly
- Caucasians, flat,
slowly growing black lesion
acral lentiginous features
- rare
- Nails, palms or soles, People with darker skin pigmentation
- Subungual pigmentation (Hutchinson’s sign) or on palms or feet
Kaposi Sarcoma
- Tumour of vascular and lymphatic endothelium.
- Purple cutaneous nodules.
- Associated with immuno supression.
- Affects elderly males and is slow growing.
- Immunosupression form is much more aggressive and tends to affect those with HIV related disease. HHV8
Pyogenic granuloma
- Overgrowth of blood vessels.
- Red nodules.
- Usually follow trauma.
- May mimic amelanotic melanoma.
Hereditary haemorrhagic telangiectasia
Need 2-3/4 to diagnose:
1. epistaxis : spontaneous, recurrent
2. telangiectases: multiple at characteristic sites (lips, oral cavity, fingers, nose)
3. visceral lesions: for example gastrointestinal telangiectasia (+/-bleeding), pulmonary arteriovenous malformations (AVM), hepatic AVM, cerebral AVM, spinal AVM
4. FH: a first-degree relative with HHT
Basal cell carcinoma features
- sun-exposed sites, especially the head and neck
- initially a pearly, flesh-coloured papule with telangiectasia
- may later ulcerate leaving a central ‘crater’
Mx of basal cell carcinoma
- routine referral should be made
- surgical removal
- curettage
- cryotherapy
- topical cream: imiquimod, fluorouracil
- radiotherapy
Bowen’s disease features
- precancerous dermatosis that is a precursor to squamous cell carcinoma
- red, scaly patches, slow growing, on sun exposed areas
Mx of bowen’s disease
- topical 5-fluorouracil BD for 4 weeks
- meds often results in significant inflammation/erythema. Topical steroids are often given to control this
- cryotherapy
- excision
pathway of SCC formation
actinic keratosis –> bowen’s –> SCC
erythema multiforme features
- hypersensitivity reaction
- target lesions
- initially seen on the back of the hands / feet before spreading to the torso
- upper limbs > lower limbs
- pruritus is occasionally seen and is usually mild
erythema multiforme causes
- viruses: HSV (most common), Orf
- idiopathic
- bacteria: Mycoplasma, Strep
- drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, oral contraceptive pill, nevirapine
- connective tissue disease e.g. SLE
- sarcoidosis
- malignancy
erythema multiforme major
more severe form
associated with mucosal involvement
Bullous pemphigoid features
- autoimmune condition causing sub-epidermal blistering of the skin
- itchy, tense blisters typically around flexures
- blisters usually heal without scarring
- stereotypically no mucosal involvement (i.e. the mouth is spared)
Ix for bullous pemphigoid
immunofluorescence shows IgG and C3 bind to hemidesmosomes of BM at the dermoepidermal junction
Mx of bullous pempihgoid
- referral to a dermatologist
- oral corticosteroids 1st line
- topical corticosteroids, immunosuppressants and antibiotics are also used
Pemphigus vulgaris features
- autoimmune disease
- Ashkenazi Jewish population
- mucosal ulceration is common
- flaccid, easily ruptured vesicles and bullae.
- painful non itchy lesions
- Nikolsky +ve
Ix for pemphigus vulgaris
IgG Abs bind to
desmoglein 1 & 3
(adhesion molecules desmosomes)
between keratinocytes
in stratum spinosum →
acantholysis
Mx of pemphigus vulgaris
- oral steroids
- immunosuppressants
rash with pain
shingles
complications is most associated with psoralen + ultraviolet A light (PUVA) therapy?
SCC
Urticaria features
- local or generalised superficial swelling of the skin
- due to allergy
- ‘hives’, ‘wheals’, ‘nettle rash’
- pruritic
Mx of urticaria
- non-sedating antihistamines (e.g. loratadine or cetirizine) up to 6 weeks
- chlorphenamine may be used at night for troublesome sleep sx
- prednisolone is used for severe or resistant episodes
Eczema herpeticum
- severe primary infection of the skin by herpes simplex virus 1 or 2
- children with atopic eczema
- presents as a rapidly progressing painful rash
- monomorphic punched-out erosions (circular, depressed, ulcerated lesions) usually 1-3 mm
Mx of eczema herpeticum
- refer to secondary care
- IV aciclovir
Cherry haemangioma features
- benign skin lesions which contain an abnormal proliferation of capillaries
- increasing age RF
- erythematous, papular lesions
typically 1-3 mm in size - on-blanching
- not in mucous membranes
- Mx: nil
pyoderma gangrenosum features
- rare, non-infectious, inflammatory disorder
- very painful skin ulcer
- lower legs most common site
- can also have systemic sx
causes of pyoderma gangrenosum
- idiopathic 50%
- IBD
- RA and SLE
- haematological e.g. myeloproliferative disorders, lymphoma, myeloid leukaemias
- granulomatosis with polyangiitis
- PBC
Mx of pyoderma gangrenosum
the potential for rapid progression
- oral steroids
- immunosuppressive therapy in difficult cases
lichen sclerosis features
- itchy white lesion on elderly vulva
Mx of lichen sclerosis
topical steroids and emollients
what does lichen sclerosis increase risk of
vulval cancer
Hidradenitis suppurativa features
- chronic, painful, inflammatory skin disorder
- inflammatory nodules, pustules, sinus tracts, and scars in intertriginous areas (axilla MC)
- F > M , <40y/o
- ‘rope-like’ scarring
- sweat related
Mx of hiradenitis suppurativa
- good hygiene and loose-fitting clothing
- Smoking cessation
- Weight loss in obese
- Acute flares: steroids (intra-lesional or oral) or flucloxacillin. Surgical incision and drainage may be needed
- Long-term: topical (clindamycin) or oral (lymecycline or clindamycin and rifampicin) antibiotics.
- Lumps that persist are excised
Tinea corporis (ringworm)
- causes include Trichophyton rubrum and Trichophyton verrucosum (e.g. From contact with cattle)
- well-defined annular, erythematous lesions with pustules and papules
- Mx oral fluconazole
what burns needed fluid resus
> 15% body area
side effect of ketoconazole
gynaecomastia
livedo reticularis features
purplish, non-blanching, reticulated rash caused by obstruction of the capillaries –> swollen venules
causes of livedo reticularis
- idiopathic (most common)
- polyarteritis nodosa
- SLE
- cryoglobulinaemia
- antiphospholipid syndrome
- Ehlers-Danlos Syndrome
- homocystinuria
keratoacanthoma features
- benign epithelial tumour.
- common with advancing age
- look like a volcano or crater
- initially a smooth dome-shaped papule
- rapidly grows to become a crater centrally-filled with keratin
Mx of keratoacanthoma
- Spontaneous regression within 3 months is common, often resulting in a scar.
- Lesions should be urgently excised as it is difficult clinically to exclude squamous cell carcinoma
Keloid scars
- tumour-like lesions that arise from the connective tissue of a scar and extend beyond the dimensions of the original wound
- common in darker skin
Mx of keloid scars
- early: intra-lesional steroids e.g. triamcinolone
- excision is sometimes required but can create further keloid scarring
Venous ulceration mx
- compression bandages
- oral pentoxifylline, a peripheral vasodilator, improves healing rate
how to differentiatie toxic epidermal necrolysis from Staphylococcal Scalded Skin syndrome
SSSS- neonates and young children
TEN- drug induced
uncircumcised man, who has developed a tight white ring around the tip of the foreskin and phimosis
lichen sclerosis
most effective treatment for prominent telangiectasia in rosacea
phototherapy
Erythema ab igne
caused by infrared radiation and is commonly associated with hot water bottles or open fires
single most important prognostic factor of melanom
depth
Breslow thickness
squamous cell carcinoma RFs
- excessive exposure to sunlight / psoralen UVA therapy
- actinic keratoses and Bowen’s
- immunosuppression e.g. following renal transplant, HIV
- smoking
- long-standing leg ulcers (Marjolin’s ulcer)
- genetic conditions e.g. xeroderma pigmentosum, oculocutaneous albinism
squamous cell carcinoma features
- sun-exposed sites
- rapidly expanding painless, ulcerate nodules
- cauliflower-like appearance
- there may be areas of bleeding
Mx of squamous cell carcinoma
Surgical excision
- 4mm margin if lesion <20mm
- >20mm then 6mm margin
- Mohs micrographic surgery may be used in high-risk patients and in cosmetically important sites.
signs of zinc deficiency
- Dermatitis (red crusted lesions) in acral, peri-orificial and perianal distribution
- alopecia
- short stature
- hypogonadism
- hepatosplenomegaly
- geophagia (ingesting clay/soil)
- cognitive impairment
niacin deficiency (pellagra)
- vitamin b3 def
- diarrhoea, dermatitis, and dementia
vitamin c deficiency
- scurvy
- ecchymoses, perifollicular haemorrhages, and corkscrew hairs and purpura.
Stevens-Johnson Syndrome causes
- severe systemic reaction affecting the skin and mucosa that is almost always caused by a drug reaction
- penicillin
- sulphonamides
- lamotrigine, carbamazepine, phenytoin
- allopurinol
- NSAIDs
- oral contraceptive pill
Features of Stevens-Johnson Syndrome
- rash (<10% BDSA) is maculopapular with target lesions being characteristic
may develop into vesicles or bullae - Nikolsky sign is positive in erythematous areas - blisters and erosions appear when the skin is rubbed gently
- mucosal involvement
- systemic symptoms
actinic keratosis vs seborrhoeic keratosis
AK: pre-malignant, red rough scaly patches
SK: benign, brown stuck on appearance
how to assess depth of burns
- Superficial epidermal: 1st degree Red and painful, dry, no blisters
- Partial thickness (superficial dermal): 2nd degree
Pale pink, painful, blistered. Slow capillary refill - Partial thickness (deep dermal): 2nd degree
Typically white but may have patches of non-blanching erythema. Reduced sensation, painful to deep pressure - Full thickness: 3rd degree
White (‘waxy’)/brown (‘leathery’)/black in colour, no blisters, no pain
Causes of pruritis
- liver disease
- iron deficiency anaemia
- polycythaemia
- CKD
- lymphoma
erythroderma features
when more than 95% of the skin is involved in a rash of any kind.
causes of erythroderma
- eczema
- psoriasis
- drugs e.g. gold
- lymphomas, leukaemias
- idiopathic
conditions that psoriasis increases the risk of
cardiovascular disease
lymphoma
non-melanoma skin cancer
erythema nodosum features
- inflammation of subcutaneous fat
- tender, erythematous, nodular lesions
- over shins, also elsewhere (e.g. forearms, thighs)
- usually resolves within 6 weeks
lesions heal without scarring
causes of erythema nodosum
NODOSUM
No- idiopathic
D- drugs (penicillins, sulphonamides)
O- oral COCP/pregnancy
S- sarcoidosis
U- UC/Crohn’s Behcet’s
M- microbiology infection (streptococci, TB, brucellosis), malignancy
port wine stain
- vascular birthmarks that tend to be unilateral
- deep red or purple
- do not spontaneously resolve, darken and become raised over time
Port wine stain mx
cosmetic camouflage or laser therapy (multiple sessions are required)
Hyperhidrosis
excessive sweat production
Mx for hyperhidrosis
- topical aluminium chloride 1st line SE skin irritation
- iontophoresis: useful for patients with palmar, plantar and axillary hyperhidrosis
- botulinum toxin: for axillary sx
- surgery: e.g. Endoscopic transthoracic sympathectomy. Patients should be made aware of the risk of compensatory sweating
Strawberry naevus
- not present at birth but may develop rapidly in the first month of life
- erythematous, raised and multilobed tumours
- increase in size until around 6-9 months before regressing over the next few years
mx of cellulitis
flucloxacillin
calirthromycin or doxycycline if penicillin allergy
erythromycin if pregnant
