Dermatology and miscellaneous Flashcards
Functions of skin? Proliferation of skin in what layer? What is desquamation? pH of skin?
Barrier to infection, thermoregulation, protection against trauma, protection against UV, via D synthesis, regulate H20 loss
Just in the basal layer
Mature corneocytes are shed from the surface of the stratum corneum- corneo-desmosomes are degraded due to proteases
5.5- proteases can remain on the skin
3 layers of skin?
Epidermis- stratum corneum= outermost made up of corneodesmosomes and desmosomes (increased in psoriasis, decreased in atopic eczema,) stratum lucidum, granulosum, spinous, basal (dividing cells)
Dermis- Meissner’s corpuscle- light touch, Pacinian corpuscle- coarse touch/ vibration
Subcutaneous tissue- fat
Cell types of epidermis?
Keratinocytes- produce keratin as protective barrier, Langerhans cells- present antigens and activate T cells, melanocytes- produce melanin which protects from UV radiation, Merkel cells- more specialised nerve endings for sensation
Common causes of itch WITH rash? With NO RASH?
Urticaria- hives, weals, welts- raised itchy rash, atopic eczema, psoriasis, scabies- burrows between fingers
Renal failure, jaundice, iron deficiency, Lymphoma- particularly Hodgkin’s, polycthaemia, pregnancy alone, drugs, diabetes, cholestasis, as skin ages- it itches more
What does acne affect? Most common variant? Epidemiology?
Hair follicle and sebaceous gland- expansion and blockage of follicle and inflammation
Vulgaris
Starts in adolescence, often resolves in mid-20s, affects face, back and chest, usually during puberty
Pathophysiology of acne?
Narrowing of hair follicles due to hypercornification blocking entrance–> increased sebum= skin feels greasy, some sebum becomes trapped in narrow hair follicle, stagnates at pit of follicle where there is no oxygen–> p.acnes multiplies–> breaks down triglycerides into free fatty acids–> irritation, inflammation and NP attraction–> pus formation and further inflammation
Presentation of acne? Diagnosis?
Whiteheads- closed comedones, blackheads= open comedones, skin-coloured papule, inflammatory lesions- closed wall of comedones ruptures, papules, pustules, nodules, commonly on face, back and chest
Usually clinical, skin swabs for microscopy and culture, hormonal tests in females
Tx of mild and severe acne?
Mild: benzyl peroxide gel/ cream= increases cell turnover, clears pores and reduces bacterial count, causes dryness, topical ABs- clindamycin gel/ erythromycin, topical retinoids e.g. tazarotene gel (irritating)= inhibit form and number of microcomedones. SEs= burning, stinging, dryness, scaling
+ topical therapy: oral tetracyclines e.g. oral doxycycline (1st line) then oral minocycline (2nd)= 4 month minimum use, CI in pregnancy and children, hormonal tx- when ABs failed/ control of menstruation is needed, anti-androgen tx= suppress sebum production e.g. oral co-cyprindiol
What does eczema/ dermatitis describe? Epidemiology? 2 types?
Common group of inflammatory skin diseases- breakdown of skin due to thinning of stratum corneum- increased risk of inflammation
Genetically complex, familial disease- strong maternal influence, 10% population, 40% episode in lifetime, high prevalence in 15-30% children and 2-10% adults, nearly always itchy
Endogenous(atopic)- usually due to hypersensitivity, exogenous- contact dermatitis usually from chemicals, sweat and abrasives
Causes of eczema? Risk factors? Pathophysiology? Presentation?
Thought to be from damaged filaggrin= skin barrier protein, exacerbated by chemicals, detergents and woollen clothes, infection either in skin/ systematically–> exacerbation by super-antigen effect
Family history- faulty gene for filaggrin
Initial TH2 activation –> inflammation
On face and flexure of limbs, itchy erythematous and scaly patches in flexure and around neck, increased dryness, infants= cheeks–> body, very acute lesions may weep/ exude and can show small vesicles, recurrent s.aureus may be common
Diagnosis of eczema? General advice? In healthy skin barrier, there are? In defective barrier e.g. in eczema?
Atopic dermatitis: clinical, high serum IgE in 80%, itchy skin condition in past 6 months + 3/ more of: history of involvement of skin creases, personal history of asthma/ hay fever, history of dry skin, onset in childhood
Education and explanation, avoidance of irritants/ allergens, keep nails short
Swelled corneocytes filled with NMF= retain moisture, lipid bilayers prevent water loss between corneocytes
Loss of NMF–> dry skin and cracks, abnormal lipid bilayer= inadequate perm barrier
In emollients e.g. E45 cream there is artificial restoration of what? Application how often? Dosage in child and adult? Compliance is significantly correlated with what?
Barrier in skin with defective barriers- trap moisture in skin and increase hydration, artificial perm barrier above stratum corneum= prevents water loss between corneocytes
Every 4 hours/ 3-4 times per day: 250-500g per week, 500-750g per week
With clinical improvement
1st and 2nd line tx for topical therapies for eczema? Classification of topical corticosteroids? What do they do? SEs?
Topical corticosteroids, topical calcineurin inhibitors
Very potent- only on thick skin- clobetasol propionate, potent- flucinonide, moderate- clobetasol butyrate, mild- hydrocortisone
Directly and indirectly inhibit pro-inflame cytokines e.g. IL-1, -2,-6 and TNF-alpha
Skin atrophy, suppression of skin barrier homeostasis, telangiectasia, thinning of skin, acne, striae, only steroids on inflamed skin!
Features of topical calcineurin inhibitors and e.g.s? Does what? SEs?
Slightly less effective- less SEs and more useful for sensitive areas e.g. pimecrolimus/ tacrolimus ointment
Inhibits calcineurin- induces trans factors for many interleukins e.g. IL-2= activate Th cells, reduce inflammation, do not cause skin atrophy
Burning, stinging following application
Tx for moderate- severe/ non-responsive?
Oral immune-modulators: ciclosporin, azothioprine, be aware of immune-suppression effects, oral steroids e.g. prednisolone, ABs e.g. flucloxacillin, phototherapy with UV A, antihistamines e.g. chlorphenamine
Sedate pt- get good rest and better sleep
What is psoriasis? Epidemiology? Risk factors?
Chronic inflammatory skin disease due to hyperproliferation of keratinocytes and inflammatory cell infiltration
2% of UK population, onset= any age- uncommon in children, peak in early adulthood, second peak= 50-60 years, equally in men and women, opposite to eczema
Polygenic, environmental triggers: infection with group A streptococcus, drugs e.g. lithium, UV light, high alcohol use, stress, family history
Pathophysiology of psoriasis? Presentation?
T-cell activation–> up regulation of TH1 cytokines e.g. interferon gamma, interleukins, growth factors and adhesion molecules–> hyper proliferation of keratinocytes in epidermis and increased cell turnover rate
Nail changes- pitting and onycholysis(separation from nail bed,) chronic plaque psoriasis: most common, well-demarcated disc-shaped, salmon-pink silvery plaques on exterior surface of limbs- elbows and knees, scalp involvement common- most at hair margin, thickened epidermis, new plaques at sites of skin trauma
Tx for psoriasis?
Emollients, topical vit D analogues: calcipqotriol cream/ ointment, topical corticosteroids- hydrocortisone cream, topical retinoids e.g. tazarotene gel, ultraviolet B, coal tar, anti-mitotic e.g. dithranol cream= large plaques only
Extensive plaques: phototherapy with UV A, DMARD= inhibits folic acid met and DNA rep, folic acid supplements 48 hrs after tx e.g. oral methotrexate- SEs= hepatotoxic, CI= pregnancy, breast feeding, hep disease/ alcoholism, renal impairment, active infection, live vaccines
Immunosuppressant- e.g. ciclosporin
3 types of psoriasis? What is fleuxural? Tx?
Flexural, guttate (raindrop-like,) palmoplantar
Later in life, well-demarcated red, glazed, non-scaly plaques, scaling= absent, flexures- groin, natal cleft and sub-mammary areas, mistaken for candida intertrigo
Hydrocortisone/ clobetasol butyrate, calcipotriol cream
Guttate psoriasis most common in who? Tx?
Children and young adults, conc on trunk, upper arms and legs
Explosive eruption of very small circular or oval plaques over trunk about 2 weeks after streptococcal sore throat
Hydrocortisone, clobetasol butyrate, ultraviolet B, coal tar
What is palmoplantar psoriasis? Tx? Anti-TNF biologics only used when?
Thickening of palms and soles
Emollients, keratolytic agents e.g. salicylic acid, flucinonide, phototherapy with UV A, oral retinoid- oral acitretin
Once systemic therapy has failed- IV infliximab, etanercept or IV adalimumab
SCC presents when? What is it? More aggressive than what? What is Bowen’s disease?
In later-life, locally invasive, malignant tumour of the squeal keratinocytes
Than BCC- higher metastatic potential, part to lymph nodes, 2nd most common below BCC
In situ SCC confined to epidermis
Risk factors for SCC? Presentation and tx?
UV exposure, chronic inflammation e.g. wound scars and immunosuppression
Most common on sun-exposed sites in later-life, lesions often keratotic- ill-defined nodules may ulcerate, can grow very rapidly, ulcerated lesions on lower lip/ ear= often more aggressive, examination of regional lymph nodes= essential for mets
Surgical excision with minimal margin of 5mm, radiotherapy also- esp if non-resectable
Most common malignant skin cancer? 95% is what? Resemble what when pigmented? Majority in who? May what? Tumour of what? Presents when?
Basal cell carcinoma Non-pigmented Melanoma In elderly on head and neck Ulcerate- 'rodent ulcer' Of the basal keratinocytes In later life Rarely mets but is locally destructive, slow-growing, locally invasive
RFs for BCC? Presentation and tx?
UV exposure, skin type 1L burns and doesn’t tan, ageing
Border of ulcerated lesions raised with pearly appearance
Slowly enlarging, shiny nodule on head and neck- bleeds following minor trauma and does not heal
Slowly–> local tissue destruction if not treated
Surgery excision with wide borders and histology- ensure clear and adequate tumour margins
Superficial= non-surgical- cryotherapy, photodynamic therapy, radiotherapy cannot tolerate surgery
Most malignant form of skin cancer? Epidemiology? RFs?
Malignant melanoma
Malignant tumour of melanocytes
Younger patients, most deaths by cancer in men, excessive sun exposure and sunburn in childhood, in more affluent people- heavy alcohol+ sun exposure
UV exposure, red hair, high density freckles, skin type 1: skin burn and not tan, atypical moles, multiple melanocytes naevi- benign, sun sensitivity, immunosuppression, FH, pale skin
Presentation of malignant melanoma?
Commonest in men= back/chest, women= lower legs
>95%= dark colour, black/ almost black in part of lesion
ABCDE: asymmetrical shape, border irregular, colour irregular, diameter> 6mm, elevation/ evolution- change of lesion
Major signs= change in size, shape or colour
Minor= inflammation, crusting, bleeding, sensory change, itching
Types of melanoma? Diff diagnosis?
Superficial spreading (SSMM,) nodular-most aggressive, lentigo maligna- usually on face acral- restricted to palms/ soles Benign pigmented naevus, seborrheic wart- elderly, pyogenic granuloma- small warty lesion bleeds easily, non-pigmented when minor trauma, benign lesion that grows quickly
Tx of malignant melanoma? Distant mets commonest to where? Prognosis?
Surgical excision in curative in early cases, very wide excision does not improve survival, limited sensitivity–> radiotherapy, met disease (30-50%)= removal of regional lymph nodes, isolated limb perfusion, RT, immunotherapy and CT
Lung, liver, CNS- any tissue/ organ can be affected
Thin lesions= best prognosis, over 60= lower 5 year survival, female advantage, ulceration= late-stage sign, poor if on trunk vs limbs
What is cellulitis? Pref involves what? Aetiology? RFs?
Bacterial infection of the deep sub-cut tissues
The lower extremities
Group A Beta- haemolytic streptococcus e.g. streptococcus pyogenes most common, s.aureus, sometimes MRSA
Lymphoma, leg ulcer, immunosuppression, traumatic wounds, athletes foot, leg oedema, obesity
PP of cellulitis? Presentation?
Lower leg/ arm and spreads proximally, other= abdomen, perianal and periorbital areas, just one side of face
Local inflam- proximally spreading, hot erythema in affected area, poorly demarcated margins, swelling, warmth and tenderness, blister- esp if oedema is prominent, systemic unwell with pyrexia
Diagnosis and tx of cellulitis?
Clinical, skin swabs are usually negative unless taken from broken skin, serological to confirm streptococcal infection e.g. antistreptolysin O titre (ASOT)
ABs: oral phenoxymethylpenicillin/ oral flucloxacillin
Oral erythromycin in pen allergy
Widespread infection–> ABs IV for 3-5 days, then 2 weeks oral therapy
Recurrent–> prophylaxis low-dose ABs e.g. oral phenoxymethylpenicillin twice daily
What necrotising fasciitis? Two forms?
Deep-seated infection of subset tissue–> fulminant and spreading destruction of fascia and fat, initially spares the skin= high mortality
Type 1: mixture of aerobic and anaerobic bacteria, following abdo surgery or in diabetics
Type 2: group A beta-haem strep e.g. strep pyogenes- most common
RFs and presentation of necrotising fasciitis?
Abdo surgery, immunosuppression
Severe pain out of proportion to skin findings at initial site of infection, rapidly followed by tissue necrosis, track rapidly along tissue planes= spreading erythema, pain and sometimes crepitus (crackling when joint moves)
Fever, toxicity and pain out of proportion to skin findings , multi-organ failure= common
Diagnosis and tx of necrotising fasciitis?
Soft tissue gas is seen on XR, raised CRP, very raised white cell count, treat aggressively and promptly
GAS- type 2: IV benzylpenicillin and IV clindamycin
Unknown aetiology- type 1: broad spec IV ABs with inclusion of IV metronidazole
Urgent surgical exploration with ext debridement or amputation if necessary
What are venous ulcers described as? They are a result of what? Epidemiology?
Defined as a loss of skin below the knee on the leg or foot that takes more than 2 weeks to heal
Result of sustained venous HTN in the superficial veins
Most common type in the developed world
Common in later life and are costly as they are often chronic and recurrent
Affect 1% over 70 y/o
Most commonly found on the lower leg in a triangle above the ankles
Aetiology of venous ulcers? RFs and pathophysiology?
Sustained venous HTN that is caused by: incompetent valves in the deep or perforating veins, previous DVT, atherosclerosis, vasculitis e.g. RA, SLE
Varicose veins/ DVT
Increased pressure–> extravasation of fibrinogen through capillary walls–> rise to perivascular fibrin deposition–> poor oxygenation of surrounding skin
Presentation and diagnosis of venous ulcers? Tx?
Sloping and gradual edges, ulcer= large, shallow, irregular and exudative, usually minimal pain, oedema of the lower leg, venous eczema, brown pigmentation from haemosiderin, varicose veins, pulses present, warm skin
Ankle brachial pressure index (ABPI)= normal, Doppler US to exclude significant arterial disease
High compression 4 layered bandage, leg elevation to reduce venous HTN, ABs for infection, analgesia e.g. ibuprofen/ even morphine, support stockings for life
What are arterial ulcers? Epidemiology? RFs? Presentation?
Punched-out, painful ulcers higher up the leg or on the feet
History of claudication, HTN, angina or smoking
Arterial disease e.g. atherosclerosis, smoking, hypercholesterolaemia, diabetes mellitus
Punch-out ulcers higher up the leg/ or on the feet, intense pain worse when elevated, leg= cold and pale, ulcer= small, sharply defined and has a necrotic base, shiny pale skin and loss of hair, absent peripheral pulses, arterial bruits- murmurs often due to partial obstruction in artery, no oedema
Diagnosis and tx of arterial ulcers?
Doppler US will confirm arterial disease, ABPI suggest arterial insufficiency
Keep ulcer clean and covered, analgesia e.g. ibuprofen/ even morphine, vascular reconstruction if appropriate, never use compression bandaging
Neuropathic ulcers are often what? Tend to be seen over what? Most commonly found in who? Common cause in some developing countries?
Painless
Over pressure areas of feet, such as the metatarsal heads or heels owing to repeated trauma
In diabetes and neurological disease due to peripheral neuropathy
Leprosy
Neuropathic ulcers tend to have variable what and may be surrounded by what? There is what and what? Tx?
Size
Callus
Warm skin and normal peripheral pulses
Keep ulcer clean and remove pressure or trauma from the affected area, correctly fitting shoes and specialist podiatrist help for diabetics
Cutaneous vasculitis may be what or what? Most common of this? Usually appears where? Rarely ass with what? Causes?
An isolated problem or part of a systemic disease with involvement of other organs
Leucocytoclastic vasculitis (LCV)/ angiitis - affecting small vessels
On lower legs as a symmetrical palpable purpura
Systemic involvement
Majority= idiopathic, drugs, infection, inflam disease, malignant disease
Often settles spontaneously
Presentation and tx of vasculitic ulcers?
Cutaneous features which may erode and ulcerate are: haemorrhage papule, pustules, nodules, plaques
These purpuric lesions do not blanch with pressure from a glass slide
Pyrexia and arthralgia are common
Analgesia, support stockings, dapsone (antibiotic,) or prednisolone
Infective ulcers often due to what things? Swab for what?
B-haemolytic streptococcal and/ or staphylococcal ecthyma, chronic herpetic infection, syphilitic gamma, TB, atypical mycobacteria, leprosy
Gram stain and culture, at low temp if mycobacterial or fungal disease is considered
What is a traumatic ulcer? Prophylaxis for at-risk patient? Tx?
Pressure ulcer–> tissue necrosis w/ ulceration due to prolonged pressure (increased freq in ischium, greater trochanter, sacrum, heel, malleolus)
Reposition every 2 hours, massage areas prone to ulcers, clean w/ cleansing agent, give nutritional supplements (vit C and zinc), mobilise pt as soon as possible
Stage 1-2= topical ABs under sterile gauze
Stage 3-4= debridement of necrotic tissue, placement of flaps and skin grafts
RFs for breast cancer?
Related to FH, age and uninterrupted oestrogen exposure, HRT, obesity, BRCA genes, not breastfeeding, alcohol, past breast cancer
Pathology of breast cancer?
Pre-malignant= non-invasive ductal carcinoma-in-situ, seen as micro calcification on mammography Malignant= invasive ductal carcinoma= most common, invasive lobular carcinoma, medullary cancers, colloid/ mucoid
60-70%= oestrogen receptor +ve= uses oestrogen to drive cellular replication= better prognosis, 30% over-express HER2= uses perception to drive cellular replication= poorer prognosis= aggressive disease
Presentation and tests for breast cancer?
Lumps-firm and irregular, asymmetric thickening, fixed–> muscle, skin tethering, nipple changes, Paget’s disease= eczema of areola, blood/ serous discharge, beau d’orange- pitted/ dimpled skin, erythema
‘Triple assessment’: physical examination and histology/ cytology (core-biopsy for solid lump, aspiration for cystic lump- US guided) + mammography/ US (only US<35 y/o, both if >35 y/o)
Staging of breast cancer?
Stage 1= confined to breast, mobile
Stage 2= growth confined to breast, mobile, lymph nodes in ipsilateral axilla
Stage 3= tumour fixed to muscle, ipsilateral lymph nodes matted and may be fixed, skin involvement larger than tumour
Stage 4= complete fixation of tumour to chest wall, distant mets
TNM staging of breast cancer?
T1<2cm, T2<2-5cm, T3>5cm, T4 fixity to chest wall, N1- mobile ipsilateral nodes; N2 fixed nodes; M1 distant mets
Tx of stage 1-2 cancer?
Surgery- by WLE+ RT to reduce recurrence or mastectomy +/- breast reconstruction + axillary node sampling/ surgical clearance or sentinel node biopsy
RT- all invasive cancer after WLE, axillary if lymph node +ve on sampling and surgical clearance not performed
Chemotherapy: adjuvant improves survival and reduces recurrence- prevents cellular rep/ daughter cells dividing e.g. antracycline + CMF, SE= infertility, hair loss
Endocrine agents: reduce oestrogen activity in oestrogen/ progesterone receptor +ve disease e.g. ER blocker (tamoxifen), aromatase inhibitors- if post-menopausal
HER 2 targeted therapy- herceptin: AC, doxorubicin, cyclophosphamide, SE= HF- needed by cardiac myocytes, scan frequently
Common sites of breast cancer mets? Histology done to assess what? Oestrogen +ve tx? Weak oestrogen? HER 2?
Aromatase inhibitor or tamoxifen
Chemo
Herceptin: AC, doxorubicin, cyclophosphamide
Supportive therapies for breast cancer? Prevent deaths how? Comps- post-op and psych?
Denosumab (sc) MAb- mops up RANK ligand/ bisphosphonates, RT, surgery and nursing for other mets
Promote awareness, screening: 2view mammography every 3 years for women aged 47-73
Bleeding, infection, delayed healing, flap failure
Young= fertility, menopause, children impact, genetics, older= burden to families, mortality, body image and intimacy issues
What is lymphoedema? Aetiology?
Localised fluid retention and tissue swelling caused by compromised lymphatic system
Primary= inherited/ birth defects of lymphatic vessels Secondary= post-irradiation therapy- prev in upper limbs, parasitic infections- filariasis from mosquito infection
Presentation of lymphoedema? Diagnosis and tx?
Achy, heaviness/ fullness, oedema, occasionally pain in affected area, advanced skin changes: discolouration, warts, hyperkeratosis, papillomatosis, deformity
Clinical exam of arms/ legs, measure oedema with circumference, diff–> unaffected limbs
Incurable, symptoms tx to minimise fluid build-up and stim flow through system: compression massage, garments, bandaging, regular exercise, healthy diet
What is amyloidosis? Amyloid deposition is also a feature of what conditions? What is primary amyloidosis?
Disorders of protein metabolism, extracellular deposits of protein in an abnormal pathological insoluble fibrillary form- resistant to degradation/ proteolysis
Alzheimer’s disease, type 2 DM and haemodialysis tx
Proliferation of plasma cell clonal cells in BM- amyloidogenic monoclonal Its- fibrillary light chain protein deposition–> organ failure and death
Clonal dominance of amyloid light chains (AL)- excreted in the urine= Bence Jones proteins, rare before 40
Amyloidosis associations to what conditions? Presentation? Tx?
Myeloma, Waldenstrom’s, non-Hodgkin’s lymphoma
Kidney: glom lesions, proteinuria, nephrotic syndrome, heart= restrictive cardiomyopathy, arrhythmias, angina, nerves= peripheral and AN neuropathy, carpal tunnel syndrome, gut= macroglossia, malabsorption/ wt loss, perforation, haemorrhage, obstruction, hepatomegaly, vascular= periorbital purpura
Tx of primary amyloidosis?
Optimise nutrition, alkylating agents, oral melphalan and prednisolone/ high dose IV melphalan with autologous peripheral blood stem cell transplantation for severe disease
Amyloid is derived where reflecting chronic inflammation? In what conditions? Affects what organs? Presentation and tx?
Serum amyloid A(acute phase protein)- in RA/UC/Crohn’s/ TB/ bronchiectasis/ osteomyelitis/ familial Mediterranean fever
Kidney, liver, spleen
Proteinuria, nephrotic syndrome, hepatosplenomegaly
Manage underlying condition
Inheritance of familial amyloidosis? Mutations in what? Produced by what?
Autosomal dominant
Transthyretin- transport protein for thyroxine and retinol-binding protein
Liver
Destabilisation precipitates following stimulation–> familial amyloid polyneuropathy (FAP), cardiomyopathy/ nephrotic syndrome
Presentation, diagnosis and tx of familial amyloidosis?
Peripheral sensorimotor and autonomic neuropathy, diarrhoea, weight loss, renal and cardiac disease
Biopsy affected tissue, positive Congo red stain + red-green birefringence under polarised light microscopy, rectum/ subcutaneous fat non-invasive for biopsy and +ve 80%
Liver transplant can cure
Suspect soft tissue sarcoma if pt presents w/swelling if what? Bone sarcoma? Sarcoma secondary to radiation damage? Commonest primary bone sarcomas in adolescence/ early adulthood? Familial?
> 5cm in diameter, enlarging, painful, deep to fascia, solid mass or recurrence at the site of previous excision
Night pain, non-mechanical and swelling not ass with the joint
Chondrosarcoma and osteosarcoma
Ewing’s sarcoma and osteosarcoma
Neurofibromatosis, retinoblastoma, Gardner’s syndrome, Werner’s syndrome, Gorlin’s syndrome
Diagnosis of sarcomas and tx?
MRI if primary, incisional biopsy, CXR, CT thorax
Primary= wide excision surgery w/ adjuvant RT
If metastatic= palliative surgery, RT/ chemo
