dermatology Flashcards
acne vulgaris- what is it how many affected, complications.
chronic inflammatory skin condition- face, back chest affected.
blockage and inflammation of pilosebaceous unit. –> presents with lesions.
95% affected- 20-35% mod or severe.
complications= scarring, hyper/po pigmentation, psychosocial problems.
S+S= papules and pustules (less than 5mm)
nodules + cysts (>5mm)
in very severe they may track and form sinuses.
how to grade acne vularis, IX, Rx + when to refer
comedones must be present for a diagnosis to be made.
clinical dx, consider associations with PCOS.
mild- non inflaimed lesions
mod- more widespread- some inflammatory pustules
severe- widespread- scarring.
Rx: many options- avoid over cleaning
fixed topical adapalene + topical benzoyl peroxide (0.1% or 0.3% + 2.5%)
OR
topical tretinoin + topical clindamycin
if severe can add oral agents – lymecycline 408mg or doxy 100mg od.
COCP can be considered as alternative to abx
refer urgently if: acne fulminans (sudden + severe)
refer routinely if conglobata (large + deep burrowing)
actinic keratosis
areas of skin damage due to sun exposure.
skin coloured yellowish/ erythematous, ill defined irregularly shaped, small, scaley locaed in sun exposed areas of the body.
occur in older men, light skin.
can progress to SCC
RF: UVB exposure
over 40
light skin
immunocomprimise
Ix: dermoscopy
biopsy if uncertain, but a clinical diagnosis.
Rx:
cryotherapy
curettage
photodynamic therapy
chemical peels
topical- flurocil, imiquimod
dermabrasion- 2nd line.
risk of malignant transformation is 6.1-10% over 10 years.
allergic contact dermatitis
a localised reaction to a mild irritant- leading to burning, itching, blistering, redness.
the most common skin disease
acute onset, hands and face most commonly, recurrent.
RF: occupational exposure, atopic dermatitis.
Ix: patch testing- with allergen suspected- gold standard.
skin biopsy can be done- but does not tell difference between dermatititic types.
Rx: avoid exposure to allergen.
severity is graded by amount + stress is gives to pt.
can give topical corticosteds
or
topical calcineurin inhibitors (tac)
high potency on torso, scalp, palms, soles
low potency on- neck, face etc.
discuss BCC
white/ pink papulo nodule/ firm plaque. can be seen as a non healing scab/ wound.
associated with solar damage.
locally aggressive but rare mets. - rodent ulcer.
RF: SUN/ UV. x-ray, arsenic exposure.
associated with aberrant hedgehog signalling pathway.
transplant recipient.
Ix: shave or punch biopsy. (shave for better cosmetics)
Rx: excision. (punch biopsy can remove up to 12mm- ix and rx in one)
if sonic hedgehog gene problem- vismodegib or sonidegib
discuss bowens disease
squamous cell carcinoma in situ - confined to epidermal layers.
all over body, related to sun/ immunosuppression.
appears as red non healing area of skin, rough surface which may catch on clothes.
Ix: dermatoscopy
biopsy- gold standard- shave/punch.
Rx:
1’ –5 flurocil cream/
imiquimod cream/
destructive therapy e.g lazr /cryo.
2’– excision.
generally quite curable as it has not spread.
discuss SCC
progressed past the in-situ stage.
much more aggressive treatment- surgical excision
low risk- 4mm
high-6mm
very high- 10 mm —- clearance margins.
mohs surgery if cosmetically sensitive.
if metastasised- mohs surgery 1st line.
discuss bullous pemphagoid
IgG mediated autoimmune reaction to components of the basement membrane.
can be induced by drugs (NSAIDS, Diuretics)
men and women equally affected, affects older (60+ usually)
most common blistering autoimmune disorder. can present initially as pruritis.
1-4cm in diameter.
Ix: biopsy (take 2 for different dies) - reveals linear igG
if: linear IgG, over 70, no skin atrophy, no mucosal or head and neck involvement- 3/4 of these pretty good diagnostic.
Rx: less than 20% BSA affected- topical (super potent- clobetasol)
systemic- pred- 0.5-1mg/kg OD. 2/52 then taper over 6-9/12.
cellulitis
infection of the deep dermis + subcut tissue. pain, warm, red, swelling. blisters, generally being unwell.
cauitive bacteria: strep pyogenes + staph aureus.
RF: prior cellulits, obesity, lymphoedema, venous insuficiency. DM,preg, immunodef.
Ix:clinical diagnosis but consider swa and growth if break in skin.
blood culture if needing admission.
Mx:
admit if- frail, unwell, sings of nec fash, orbital cellulits.
fluclox 500-1000 qds 7/7
OR
clarithromycin 500 BD
Erythromicin if pregnant 500 QDS 7/7.
complications: subcutaneous abcess
post-strep nephritis.
nec fash.
myositis
can lead to leg ulceration.
discuss eron classification of cellulitis
1- well with no comorbidities
2- unwell OR well with poorly controlled comobridies.
3- SIRS response or very poorly controlled comorbidities
4- septic shock or life threatening inf.
cutaneous lymphoma
rare type of non-Hodgkin lymphoma. more commonly T cell than B cell.
affects the skin- usually stays confined but can spread to lymph. gen good prog
very varied skin appearance- but usually quite large areas of red/ discolouration/ raised areas. becomes more nodular when progressing.
most common type is mycosis fungoides (more than half- T cell)
RF: sun exposure- possibly specific infection but not sure which one.
Ix:skin biopsy- establish clonal cells present.
blood film.
Rx: steroid/ chemotherapy cream. UVB therapy. radiotherapy.
systemic chaemo if more widespread.
(chlorambucil, methotrexate)
discuss cutaneous manifestations of malignancy
many cancers can present with cutaneous features, not just due to spread of disease - paraneoplastic syndromes can cause changes- e.g acanthrosis nigricans.
Curths criteria help establish if the skin change is related to the malignancy
1.Both conditions began simultaneously (neoplasia and paraneoplasia)
2) Development of a parallel course *
3) The skin lesion is not associated with a genetic syndrome
4) There is a specific type of neoplasia that occurs with paraneoplasia
5) the dermatosis is rare in gen pop
6) high frequency of assication between both conditions.
next flashcard (maybe) will have the examples of some on.
dermatomyositis
chronic inflammatory condition - rashes and worsening b/l muscle weakness.
1 per 100 000 new each year, peaks at 40-50
unknown cause- may be autoimmune.
associated with 6x increased risk of breast, ovarian, lung, and haematologic cancers. risk decreased after 2 years diagnosis
severe disease assoc with cardioresp symptoms and dysphagia.
ix: - 5 criteria for diagnosis
1. muscle weakness in BOTH thighs or shoulders
2. bloods- inc CK, LDH, transaminases
3. electromyography (erratic repetitive high freq + short low energy between muscles + sharp activity when needle goes in)
4. biopsy- mononuclear wbc
5. rashes (only thing diff from polio)
associated with ANA
Rx: pred 1-1.5mg/kg od
methotrexate
azathioprine
some examples of dermatological manifestations of malignancy
Acanthosis Nigricans Maligna Abdominal adenocarcinomas (gastric neoplasia)
Acquired Pachydermatoglyphia Gastric and pulmonary carcinoma
Erythema gyratum repens Pulmonary, esophageal and breast
Bazex paraneoplastic acrocheratosis Aerodigestive tract (oral cavity, larynx, pharynx, trachea, esophagus and lung)
Acquired hypertrichosis lanuginosa Colorectal, pulmonary
and breast
Necrolytic migratory erythema Glucagonoma
Leser-Trélat Sign Gastric and colorectal
Paraneoplastic pemphigus Non-Hodgkin lymphoma, chronic lymphocytic leukemia, Castleman’s disease, thymoma
discuss cutaneuous drug reactions
common- ADR usually- mainstay of treatment is removal of offending drug.
features: urticaria, pruritis, maculopapular reaction. erythema multiforme, SJS (less than 10%), TEN (more than 30%), erythema multiform (target redness)
common causitive drugs- beta lactams, anaesthetic muscle relaxants, contrast media.
Ix: serum tryptase
drug specific ige
comliment pathway assey
