derm Flashcards
what type of melanin does MRC1 produce
eumelanin (darker pigment)
outline eccrine gland
Found all over the body
Secrete sweat and are responsible for thermoregulation
outline apocrine gland
Found in axillae and perineum
Secrete oily fluid
outline sebaceous gland
Found mainly on face and chest
Secrete oily sebum which moisturises skin
Part of pilosebaceous unit
function of arrector pili muscle
contracts to cause hair to stand on end (thermoregulation)
what side effect can steroids cause
skin atrophy
what is the pneumonic for the four strength classes of steroids
Help - hydrocortisone
Every - eumavate
Budding - becnovate
Dermatologist - dermovate
outline UVA
Penetrates deeper
Taken with psoralen to enhance effect (PUVA)
Given twice weekly
Increased skin cancer risk
outline UVB
More superficial action
Narrow band UVB more effective than wide band
Given three times weekly
No increased cancer risk (more commonly used)
outline a secondary staph aureus infection to atopic dermatitis
‘golden crust’
pustules/papules
flucloxacillin
what is the treatment for eczema herpeticum
urgent acyclovir
outline seborrhoeic dermatitis
Proliferation of Malassezia fungus affecting sebaceous gland rich areas
Scaly erythematous patches often on the face and scalp
Treat with antifungal azole
outline stasis dermatitis
- Immune response against fluid collecting in lower legs
- Associated with venous insufficiency (elderly, DVT, varicose veins, peripheral oedema)
- Lipodermatosclerosis: inverted champagne bottle, hyperpigmentation
- Treat with short term potent steroid, emollient and compression
aetiology of acne vulgaris
Increased androgen production of puberty acts on sebaceous gland resulting in excess sebum
Excess sebum blocks the sebaceous gland forming comedones
give definition and management of mild acne
mainly comedones, a few papules/pustules
topical retinoid/salicylic acid (keratolytic)
give definition and management of moderate acne
comedones and many papules/pustules
add oral tetracycline/erythromycin
give definition and management for severe acne
painful, nodulocystic, scarring
isotretinoin (teratogenic, dry skin, mood disturbance)
what should be stopped in females with acne
progesterone only pill
describe the rash in rosacea
Rash is erythematous, composed of papules/pustules and telangiectasia and can cause rhinophyma
Doesn’t have comedones
causes of rosacea
Can be triggered by steroids, sunlight, spicy food, alcohol
May be increased immune response to demodex mite
management of rosacea
Preventative: avoid steroids, triggers
Topical treatments such as Azelaic acid, Brimonidine (first-line according to NICE) or Ivermectin
Topical: metronidazole
Oral: doxycycline
Aesthetic: laser therapy
what are the biopsy findings in psoriasis
neutrophilic abscesses (Munro microabscesses) and hyperkeratosis, parakeratosis
describe guttate psoriasis
self-limiting, small plaques forming over most of body, may be preceded by viral infection
describe Palmoplantar pustulosis psoriasis
pustular form affecting soles and palms
describe Erythrodermic psoriasis
massive skin erythema and shedding, may be fatal
outline lichen planus
=> Inflammatory condition, itchy purple papules on wrists/ankles
=> white laces on oral mucosa (Wickham’s striae)
=> irregular sawtooth epidermis, potent topical steroids
list the two differentials for post-viral rashes and what differentiates them
guttate psoriasis or pitryasis rosea.
Differentiate with ‘herald patch’ (pitryasis rosea)
management for Polymorphic Light Reaction (‘Prickly Heat’)
prednisolone or desensitising phototherapy
management of impetigo
Topical fusidic acid if localised, oral flucloxacillin if extensive
describe different types of hair follicle infection
Superficial = folliculitis
Deep = furuncle/boil
Carbuncle = cluster of boils (associated with PVL)
what is the most common cause of skin infection and what treatment is it sensitive to
staph. aureus
fluclox.
give the most common causative organisms in cellulitis
Staphylococcus aureus or Streptococcus pyogenes
treatment for cellulitis
IV flucloxacillin
cause of necrotising fascitis
type 1: by mixed anaerobes/aerobes following GI surgery (most common)
type 2: Streptococcus pyogenes
treatment of necrotising fascitis
Treat with urgent surgical debridement and IV antibiotics
where is the most commonly affected site in necrotising fascitis and what is this sometimes called
perineum (Fournier’s gangrene).
what bacteria is involved in syphilis
Treponema pallidum spirocheate
outline the different stages of syphilis
Primary = painless chancre
Secondary = widespread erythematous rash, mucosal ‘snail-track’ ulcers
Tertiary – multi-organ damage
treatment of syphilis
IM benzylpenicillin
what bacteria is involved with lymes disease
Borrelia burgdorferi spirocheate
symtoms and signs of lymes disease
Early = erythema migrans (expanding ‘bullseye’ target lesion)
Late = arthritis, neuropathy, encephalopathy
treatment for lymes disease
Doxycycline
what age is recommended for shingles vaccine
70
what virus causes chickenpox and shingles
varicella zoster
herpes zoster
give presentations of HSV and treatment
Primary infection in childhood (gingivostamatitis)
Reactivate in adulthood with blistering on lip (herpes libialis/cold sore)
Erythema multiforme: hypersensitivity reaction forming erythematous target lesions
Topical/oral acyclovir
give presentations, complications and management of human papilloma virus (HPV)
Causes ‘viral warts’ – rough, hyperkeratotic lesions
Regular topical keratolytic (salicylic acid) or cyrotherapy
risk factor for cervical cancer
outline molluscum contagiosum
Poxvirus, fleshy, pearlescent nodules, contagious, common in children, can be sexually transmitted, self limiting/cryotherapy
outline Herpangina
- Coxsackie virus
- painful oral mucosal blistering
- swab/stool PCR diagnosis
- self-limiting
outline hand, foot and mouth disease
- Coxsackie enterovirus
- discolored lesions on hands,
feet and mouth - presents in children and family outbreaks
outline Erythema infectiosum (slapped cheek disease)
- Parovirus B19
- slapped cheek appearance and
macular rash - can cause chronic anaemia
- diagnose with IgM blood test
Infection from farm animal, firm fleshy nodule, self limiting, common in farmers
orf
what stimulates sebaceous gland
androgen
how long does it take for molluscum to resolve
18 months
describe koebners phenomenon
presence of a new skin lesion on previously healthy skin following trauma
satellite lesions
candida
treatment for candida
topical azole/nystatin
who is candida common in
diabetics
annular lesions (‘ringworm’)
dermatophyte
treatment for scabies
Topical permethrin overnight (all skin below neck)
outline Norwegian scabies
form of scabies affecting elderly or immunocompromised, crusting lesions containing thousands of mites
treatment for lice
Treat with dimeticone wash
describe Sebhorrhoeic Keratosis
Common benign lesion in elderly
Rough/warty, ‘stuck on’ appearance
describe solar letignes
Common benign lesion in elderly
Pigmented patch on sun exposed site
dysplastic meaning
pre-malignant
side effect of lamotrigine use
steven jonsoooon syndrome
what protein controls freckles/red hair
MC1R protein
what scoring system is used to predict reoccurrence of melanoma’s
Breslow Thickness
when should a sentinel node biopsy be done
Breslows thickness> 1mm
staging of melanoma
Stage 0 = 0.5cm
Stage I = 1cm
Stage II = 2cm
where do acral lentigenous melanomas occur
soles palms and nail beds
outline seborrhoeic keratosis (basal cell papillomas)
- Benign proliferation of epidermal keratinocytes
- Very common in ageing skin
- Eruptive appearance of many lesions may indicate internal malignancy - Leser-Trelat sign
greasy stuck on appearance
seborrhoeic keratosis
management of seborrhoeic keratosis
- Reassurance, most need no treatment
- If patient would like removal - cryotherapy, curettage
treatment for bowens disease/actinic keratosis
Removal (cryotherapy/curretage)
+/- Topical 5-fluorouracil/imiquimod
BCC
Nodular: painless, slow growing, pearly, aborising vessels, central ulceration
SCC
Painful, fast growing, hyperkeratotic, bleeding, inflamed, poorly defined
what gene is associated with malignant melanoma
BRAF
management for different sizes of melanoma
In situ => Excision 0.5mm margins
1mm > Excision 1cm margins
1mm < Excision 1cm margins
+ sentinel node biopsy
Metastatic (BRAF +ve) => Trametenib
outline erythema nodosum and its associated condition
tender, erythematous nodules on legs, associated with sarcoidosis
outline Necrobiosis lipodica and its associated condition
yellow/brown/red patches on legs, associated with diabetes
outline Acanthosis nigricans and its associated condition
Acanthosis nigricans: skin thickening/pigmentation in flexural areas, associated with diabetes
outline Dermatitis herpetiformis and its associated disease
immunobullous disease characterised by itchy vesicular rash, associated with coeliac disease
heliotrope rash
dermatomyositis
outline arterial ulcer
Caused by poor arterial blood supply
Hypertension, smoking, obesity, peripheral vascular disease
Punched out, painful
Hygiene, analgesia, vascular surgery
Avoid compression
outline venous ulcer
Caused by poor oxygenation secondary to venous hypertension
Peripheral oedema, stasis dermatisis, lipodermatosclerosis
Commoner, painless, medial malleolus
Compression, diuretic, support
stockings for life
ABPI < 0.5
Severe arterial disease, no compression
ABPI 0.5-0.8
Aterial disease, avoid compression
ABPI 0.8-1.3
No arterial disease, compression safe
ABPI>1.3
Calcified vessels
Immunofluorescence shows honey-comb arrangement
PEMPHIGUS VULGARIS
Immunofluorescence shows linear arrangement
BULLOUS PEMPHIGOID
Investigations for dermatitis herpetiformis
Bloods- Anti-TTG
Biopsy
- Immunoflorescence - will show granular deposits of IgA in dermal papillae
- Histology - sub-epidermal blisters with papillary micro-abscesses
treatment for dermatitis herpetiformis
Gluten free diet +/- dapsone
management of mild eczema
Topical steriod
management of moderate eczema
- Moderate topical steriod e.g. betamethasone valerate 0.025% or clobetasone butyrate 0.05%
- If face affected start with mild steroid in that area
presentation of keratocanthoma
- Develop as a red papule with a central crater-like, crusty keratinous plug
- Occur on sun-exposed skin in later life and often reach 2–3 cm in diameter
give topical treatment for large patches of actinic keratosis
Topical 5-Fluorouracil
what dermatological condition is associated with crohn’s disease/UC
pyoderma gangrenosum
tear drop lesions
guttate psoriasis
punched out erosions
eczema herpeticum
exclamation mark hairs
alopecia areata
chickenpox
Fever initially
Itchy, rash starting on head/trunk before spreading. Initially macular then papular then vesicular
Systemic upset is usually mild
measles
Prodrome: irritable, conjunctivitis, fever
Koplik spots: white spots (‘grain of salt’) on buccal mucosa
Rash: starts behind ears then to whole body, discrete maculopapular rash becoming blotchy & confluent
mumps
Fever, malaise, muscular pain
Parotitis (‘earache’, ‘pain on eating’): unilateral initially then becomes bilateral in 70%
rubella
Rash: pink maculopapular, initially on face before spreading to whole body, usually fades by the 3-5 day
Lymphadenopathy: suboccipital and postauricular
Erythema infectiosum
Also known as fifth disease or ‘slapped-cheek syndrome’
Caused by parvovirus B19
Lethargy, fever, headache
‘Slapped-cheek’ rash spreading to proximal arms and extensor surfaces
scarlet fever
Reaction to erythrogenic toxins produced by Group A haemolytic streptococci
Fever, malaise, tonsillitis
‘Strawberry’ tongue
Rash - fine punctate erythema sparing the area around the mouth (circumoral pallor)
Hand, foot and mouth disease
Caused by the coxsackie A16 virus
Mild systemic upset: sore throat, fever
Vesicles in the mouth and on the palms and soles of the feet
koebner phenomenon conditions
- psoriasis
- vitiligo
- warts
- lichen planus
- lichen sclerosus
- molluscum contagiosum
sandpaper rash
scarlet fever
treatment for genital warts
Podophyllotoxin
Imiquimod
Cryotherapy
Trichloroacetic acid
lymphoma
Night sweats
Lymphadenopathy
Splenomegaly, hepatomegaly
Fatigue
CKD
Lethargy & pallor
Oedema & weight gain
Hypertension
polycythaemia
Pruritus particularly after warm bath
‘Ruddy complexion’
Gout
Peptic ulcer disease
iron deficiency anaemia
Pallor
Other signs: koilonychia, atrophic glossitis, post-cricoid webs, angular stomatitis
liver disease
History of alcohol excess
Stigmata of chronic liver disease: spider naevi, bruising, palmar erythema, gynaecomastia etc
Evidence of decompensation: ascites, jaundice, encephalopathy
dermatofibroma
This is a solitary firm papule/nodule that dimples when pinched. Dermatofibromas occur following injury
features of dermatitis herpetiformis
itchy, vesicular skin lesions on the extensor surfaces (e.g. elbows, knees, buttocks)
what can differentiate pemphigus vulgaris/bullous pemphigoid
mucosal involvement: pemphigus vulgaris
when may Patients may return to school or work after impetigo
when all lesions have crusted over
or
48h after treatment starts
