Derm Flashcards
What is sebum?
Produced due to narrowing of the hair follicles. It stagnates in the pit of the follicle and is why the skin feels greasy
Which bacteria casues achne?
P. acnes
S&S of acne?
Whiteheads, blackheads, skin coloured papules, inflammatory lesions, pustules and nodules
Found on the face, back and upper chest
Treatment for mild achne?
Benzoyl peroxide gel/cream, topical antibiotics e.g. clindamycin gel, topical retinoids e.g. tazarotene gel
Treatment for severe achne?
Mild treatment PLUS oral tetracyclines for 4 months e.g. doxycycline, hormonal treatment e.g. oral co-cyprindiol
What is cellulitis?
A bacterial infection of the deep subcutaneous tissues
Risk factors for cellulitits?
Lymphoedema, leg ulcers, immunosuppression, traumatic wounds, athelets foot, leg oedema and obesity
What bacteria commonly cause cellulitis?
Group A beta-haemolytic strep e.g. strep. pyogenes, MRSA ans sometimes staph. aureaus
S&S of cellulitis?
Local inflammation typically in the lower limbs and extermities, inflammation spreads proximally. Warm, tender and swollen area of inflammation which occasionally blisters.
Patient is systemically unwell with pyrexia
Treatment for cellulitis?
Antibiotics e.g. flucoxacillin/erythromycin. If infection is widespread give IV antibiotics for 3-5 days then oral for 2 weeks
What is the difference between a blackhead and a whitehead?
Whitehead = closed comedones (a clogged hair folicle) Blackhead = opened comedones
What causes eczema?
Damage to filaggrin and thinning of the stratum corneum means that the skin can be invaded more easily so is more at risk of inflammation
What are the 2 main types of dermatitis?
Endogenous - atopic dermatitis, due to a hypersensitivity reaction
Exogenous - contact dermatitis, precipitated by chemicals, sweat and abrasives (irritant or allergen)
S&S of eczema?
Itchy, erythematous and scaly patches in the flexure of the elbows, knees, ankles, wrists and around the neck. Increased skin dryness and reccurrent stap. aureus infections
How is pigmented skin affected differently in eczema?
It may become hyper- or hypo- pigmented and the extensor surfaces are involved (instead of the flexors)
What is the first-line treatment for eczema?
Topical corticosteroids. Very potent e.g. clobetasol propionate Potent e.g. fluocinonide Moderate e.g. clobetasol butyrate Mild e.g. hydrocortisone They inhibit proinflammatory cytokines
What is the second-line treatment for eczema and when is this used?
Topical Calciuneuri inhibitors e.g. pimecrolimus or tacrolimus.
They inhibit calcineurin and produce less SEs - used in sensitive areas e.g. face
What is the treatment for severe eczema?
Oral immune-modulators e.g. cyclosporine and azathioprine, oral steroids e.g. prednisolone, antibiotics e.g. flucloxacillin and antihistamines to help sleep
What is necrotising fascilitis?
A deep subcutaneous infection resulting in fulminant and spreading destruction of the fascia and fat. Initally the skin is sparred
What are the two types of necrotising fascilitis?
Type 1 - caused by aerobic/anaeorbic bacteria followin abominal surgery or in diabetics
Type 2 - caused by group A beta-haemolytic streptoccoi e.g. strep. pyogenes
S&S necrotising fascilitis?
Severe pain that is out of proportion to the skin findings, gas in soft tissues = crepitus, infection spreads rapidly and can lead to multiorgan failure and death. Fever/systemic infection signs
Treatment for necrotising fascilitis?
Type 1 = broadspectrum IV antibiotics and IV metronidazole
Type 2 = IV benzylpenicillin and clindamycin
Amputation may be necessary
What is psoriasis?
Chronic inflammatory skin disease due to hyperproliferation of keratinocytes and inflammatory cell infiltration
What symptoms are associated will all types of psoriasis?
Nail changes e.g. pitting and onycholysis
Athritis can occur in all too
S&S of chronic plaque psoriasis?
Disc-shaped salmon pink silvery plaques on the exterior surface of the limbs.
Found often at elbows, knees, sclap hair margin and trauma sites it leads to a thickened epidermis
Most common
Treatment of chronic plaque psoriasis?
Emollients, topical vitamin D analogues e.g. calcitriol ointment, UV B, topical mild corticosteroids and coal tar.
UV A and DMARDs in extensive plaques
S&S of flexural psoriasis?
Red, glazed and NON-SCALY plaques confined to teh flexures.
This occurs in later life
Treatment of flexural psoriasis?
1st line = topical mild-moderate corticosteroids e.g. hydrocortisone or clobetasol butyrate
2nd line = topical vitamin D analogue e.g. calcipotriol cream
S&S of Guttate psoriasis?
Explosive eruption of small circular plaques appreaing on the trunk 2 weeks after a step throat infection.
Most common in children and young adults
Treatment for Guttate psoriasis?
Topical mild-moderate corticosteroids e.g. hydrocortisone or clobetasol butyrate, UV B and Coal tar
S&S of palmoplantar psoriasis?
Thickening of the palms and soles
Treatment of palmoplantar psoriasis?
Emollients, keratolytic agents, potent topical corticosteroids e.g. fluocinonide, UV A, oral retinoid e.g. acitretin.
Anti-TNF biologicals if all else fails
What is a squamous cell carcinoma?
A locally invasive malignant tumour of the squamal keratinocytes which presents in later life
RF for a squamous cell carcinoma?
UV exposure, chronic inflammation and immunosuppression
S&S of a squamous cell carcinoma?
Rapid growing ill-defined nodules that may ulcerate. Lesions are often keratotic and appear on sun exposed sites
Treatment of a squamous cell carcinoma?
Surgical excision with a minimal margin of 5mm and radiotherapy
What is a basal cell carcinoma?
A tumour of the basal keratinocytes which may ulcerate (this is known as a rodent ulcer). It is generally non pigmented and is the most common malignant skin cancer, occurs later in life.
RF of a basal cell carcinoma?
UV exposure, skin type 1 (burns and doesn’t tan), ageing
S&S of a basal cell carcinoma?
Slow growing/enlarging shiny nodule on the head/neck which bleeds following minor trauma and does not heal. It is locally destructive but rarely metastasises.
Ulcerated lesions will be raised with a pearly appearance
Treatment of a basal cell carcinoma?
Surgical excision with wide borers or radiotherapy.
If superficial = cryotherapy or photodynamic therapy
What is a malignant melanoma?
This is a malignant tumour of the melanocytes. It is the most malignant form of skin cancer.
What are the types of malignant melanoma?
Superfical spreading
Nodular (most aggressive)
Lentigo maligna (usually on the face)
Acral (restriced to the palms and soles)
Risk factotors for a malignant melanoma?
UV exposure, red hair, high density freckles, skin type 1, immunosuppression and pale skin
S&S of a malignant melanoma?
Very dark colour lesions appearing commonly on the chest/back (in men) and the lower legs (in women).
Commonly metastasises to lungs, liver and CNS
Treatment of a malignant melanoma?
Surgical excision if caught early.
Metastatic disease = remove regional lymph nodes, isolate limb perfusion, radio/iummo/chemo-therapy.
What is the ABCDE diagnostic criteria for skin cancer?
A - aysmmetrical shape B - border irregularity C - colour irregularity D - diameter > 6mm E - elevation/evolution of lesion These are often seen in cancer (differentiate from mole)
What is a venous ulcer?
Loss of skin below the knee on leg/foot which takes more than 2 weeks to heal - due to sustained venous hypertension
RF for venous ulcers?
Varicose veins, DVT, incompetent vlaves in the deep veins, atherosclerosis and vasculitis
RF for arterial ulcers?
Smoking, hypercholesterolaemia, atherosclerosis, DM
RF for neuropathic ulcers?
DM, neurological disease, leprosy
RF for vasculitis ulcers?
Infection, drugs, inflammatory disease and malignancy
What are vasculitis ulcers?
An inflammatory disease of the blood vessels causing endothelial damage
S&S of venous ulcers?
Large, shallow, irregular and exudative ulcer with sloping edges. Pain is minimal, there will be oedema in the lower leg eith warm skin and venous eczema
Treatment of venous ulcers?
High compression 4 layered bandages, leg elevation, analgesia and life long support stockings
S&S of Arterial ulcers?
Small punced out painful ulcers (pain is intense and worse when elevated), necrotic base to ulcer, skin is shiny and pale with no peripheral pulse
Treatment of Arterial ulcers?
Keep ulcer clean and covered, analgesia, vascular reconstruction but NO compression bandaging
S&S of neuropathic ulcers?
Painless variablet sized ulcers surrounded by callus, ulcers tend to be on areas of pressure with warm skin and normal peripheral pulses
Treatment of neuropathic ulcers?
Keep ulcer clear, remove pressure from the affected area and provide specialist podiatry services
S&S of vasculititis ulcers?
Cutaneous features which may erode and ulcerate (e.g. haemorrhagic papules, pustules, nodules and plaques), non-blanching purpuric lesions, pyrexia and arthralgia
Treatment of vasculititis ulcers?
Often settle spontaneously, analgesia, support stockings and antibiotics (e.g. dapsone)/prednisolone
How can you tell between a venous and arterial ulcer?
Ankle brachial pressure index is raised in arterial
Doppler US confirms arterial disease
