Dermatology Flashcards
Mutation in which gene is associated with basal cell carcinoma (rodent ulcer)?
TP53 tumour supressor gene
How should a suspected melanoma be managed?
Wide local excision- 1cm around the lesion for every mm of thickness of the mole up to 3cm
Sentinel node biopsy
If metastatic- molecular analysis used to match tumour with therapeutic agent
What grading system links melanoma thickness with prognosis?
Breslow’s depth- the deeper the tumour, the higher the stage:
Stage 1 = < 1mm
Stage 2 = 1-2mm
Stage 3 = 2-4mm
Stage 4 = > 4mm
What is the ABCDE of mole examination (signs of melanoma)?
Asymmetric lesions Border irregular Colour irregularity Diameter >6mm Evolving in size
Refer patient if:
3 apply
or there’s a spontaneous change in an above factor
Or there’s itching, pain or bleeding of it
What is phimosis and how is it treated?
When the foreskin is too tight to retract it.
Normal up to 4 years, may lead to increased risk of glans inflammation (balanitis)
Rx: betamethasone cream may help, stretching exercises BD
What is paraphimosis and how should it be managed?
When a retracted foreskin becomes irreplaceable and prevents venous return of the glans.
Oedema and ischaemia may ensue.
Rx:
- Patient should try to squeeze glans
- 50% glucose can reduce oedema, ice and lidocaine
- Circumcision or dorsal slit may be required
What is balanitis and how is it managed?
Inflammation of foreskin and glans- often strep or staph
Rx:
- Antibiotics + hygiene advice
- Circumcision
What may cause pyrexia following an operation in the first 48 hours?
Atelectasis- complete or partial collapse of lung lobes as a result of not ventilating normally during surgery (requires physio)
Infection- UTI, toxic shock syndrome, chest, wound, meningitis
Immune- blood transfusion, reaction to antibiotics, malignant hyperthermia, hyperacute transplant rejection
How does management differ between actinic (solar) keratoses, bowen’s disease (SCC in situ) and squamous cell carcinomas?
Actinic keratoses + Bowen’s disease
Temperature: cryotherapy, photodynamic therapy
Chemical: fluorouracil, diclofenac gel, imiquimod (induces IFN-a)
Surgical: if SCC suspected
Squamous cell carcinoma
Excision
What are the typical features of mild acne and it’s treatment?
Comedones (black heads, white heads)
Inflammatory pustules + papules
Rx: topical retinoid
± topical abx (clindamycin), salicylic acid, benzoyl peroxide
Signs of severe acne and it’s Rx:
Nodules, cysts, scarring
Oral retinoid, isotretinoin- monitor cholesterol, LFTs, triglycerides, FBC, need contraceptive (teratogenic)
Co-cyprindiol pill- a contraceptive
Oral abx
What is the pre-malignant and maligant form of each type of skin cancer?
Actinic keratoses > Bowen’s disease (in situ) > Squamous CC
Maligna lentigo > malignant melanoma
Basal cell carcinoma
How does the management of squamous cell carcinoma differ from actinic keratoses and Bowen’s disease?
Squamous cell carcinoma- excision
only 5-fluorouracil if superficial
Bowen’s + actinic keratosis- 5-FU or cryotherapy or photodynamic therapy
Management of malignant melanoma?
Wide local excision- 1cm margin for every mm of depth up to 3cm
If Breslow thickness >1mm then shoud excise sentinel lymph node
Can send to lab for targeted molecular therapies
What is the common skin lymphoma?
Mycosis fungoides- involves CD4 T helper cells
PC: well defined red scaly patches or plaques
Causes of blisters?
Infection- herpes, insect bites Drugs- ACEi, furosemide Dermatitis herpetiformis Discoid eczema- starts with vesicles, then coin shaped Autoimmune- pemphigoid + pemphigus Trauma- burns
Difference in the pathophysiology and Rx of pemphigus + pemphigoid?
Pemphigus- IgG against desmosomal components so keratinocytes separate from each other (crazy paving)
Rx: prednisolone PO or IV Rituximab/ Ig
Pemphigoid- IgG against basement membrane
Rx: clobetasol cream (steroid)
Options for breast reconstruction following surgical mastectomy:
Tissue expanders/implants
Latissimus dorsi flap
Transverse rectus abdominis myocutaenous flap
How is surface area of a burn estimated?
9% each arm 9% front of leg + 9% of back 18% front torso 18% back torso 9% whole head
Volume of Hartmanns to be given in a burn?
4 x kg x body surface area burned
1/2 given in 1st 8hrs
Rx of tinea infections
Terbafine or clomitrazole on skin
Rx of seborrhoeic dermatitis
Ketoconazole shampoo
Rx of candida in mouth and vagina:
Mouth- nystatin
Clomitrazole cream + pessary in vagina
Rx of impetigo
Superficial infection from staph aureus characterised by honey-coloured crusts on erythematous base
Topical fusidic acid
PO flucloxacillin if severe
Cause of erysipelas, common way it presents?
Strep pyogenes
Erythema of the face which is sharply defined and superficial
PO penicillin
Difference between cellulitis and erysipelas?
Cellulitis is deeper and less sharply demarcated- needs benzylpenicllin + flucloxacillin whereas erysipelas only needs penicillin (strep pyogenes)
Erysipelas affects the upper dermis whereas cellulitis affects SC fat + dermis
Management of genital warts (condylomata acuminata):
Cryotherapy
± podophyllin or imiquimod cream
Screen for other STIs
May need yearly cervical screening- risk of HPV 16+18
Management of generalised pustular psoriasis (derm emergency):
Conservative: emollients, wet dressings
Medical: oral retinoid (acitretin)- LFTs,, glucose, lipids
Biologics (etanercept)- TNFa blocker
What is the definition of erythroderma and it’s management?
Erythema and scaling of >90% of the skin surface, caused by inflammation
Conservative: Fluid balance + temperature Emollients + topical steroids Antihistamines Wet dressings
Management of eczema:
Conservative: emollients + soap substitutes
Medical:
Topical steroids (hydrocortisone or potent betamethasone)
Tacrolimus (calcineurin inhibitors)
5 types of eczema:
Atopic Venous Discoid Pompholx- hands + feet blisters Asteatotic- old age
Allergic contact dermatitis is what type of hypersensitivity reaction?
Type 4
Ie allergy to nickel, lanolin
Rx of acne rosacea?
Inflammatory erythematous telangiectasia
Inflammatory nodules, unlike acne there are no comedones
Rx:
- metronidazole
- Anitbiotics, oral retinoid
Rx of plaque psoriasis:
- Emollients + soap substitutes
Vitamin D analogue- calcipotriol
Topical steroid - Tar, Dithranol
UV A + Psoralen - If arthropathy of severe:
Oral retinoid- Acetretin
Immunosupression- ciclosporin, methotrexate
Biologics- etanercept
Stages of pressure sore:
1: non-blanching erythema
2: partial thickness skin loss
3: full skin loss extending into fat
4: destruction of bone, muscle or tendons
Features of depression:
A: anhedonia, low mood, low energy
B: low concentration, self-esteem,
guilt, unworthiness, pessamistic thoughts, self harm,
reduced sleep and appetite
Mild = 2A + 2B Moderate = 2A + 3B Severe = 3A + 4B
Hypomania features
4 days of elevated mood or irritable and 3 of: High activity or restless More distractible Less need for sleep
More talkative
More sociability
More sexual energy
Mild reckless or irresponsible behaviour
What is the difference between hypomania and mania:
Hypomania- Sx for 4 days
Mania- Sx for 1 week
Mania includes flight of ideas, loss of inhibition, severe interference of personal function
Features of serotonin syndrome:
Cognitive: headache, agitated, confused, hallucinating, coma
Autonomic: sweating, shivering, hyperthermia, nausea, high BP+HR
Somatic: myoclonus, hyper-reflexia, tremor
Signs of lithium toxicity:
GI disturbance, muscle weakness, drowsy, blurred vision
Differential of a midline neck lump:
Subcutaneous cyst
Lipoma
Lymph node
Thyroid nodule
Thryoid gland
Thyroglossal cyst
Differential of a lump in the anterior triangle of the neck?
Anterior to sternocleidomastoid:
Subcutaneous cyst
Lymph node
Lipoma
Salivary gland swelling Laryngocele- reducible Branchial cyst (failed obliteration of branchial cleft) Carotid aneurysm- pulsatile + bruit Carotid body tumour
Differential for lumps in the posterior triangle of the neck:
Subcutaneous cyst
Lymph nodes
Lipoma
Branchial cyst
Subclavian artery aneurysm- pulsatile
Pharyngeal pouch- reducible
Cystic hygroma- fluctuant
Differences between venous, ischaemic and neuropathic ulcers?
Venous:
Superficial painful ulcer in the gaiter region with sloping edges, which is pink in colour + granulating
Ischaemic:
Deep punched out ulcer on the sole/pressure areas, which appears sloughy and pale and painful
Pressure:
Deep punched out ulcer on the sole/pressure areas, which appears sloughy and pale but is not painful
