Dermatology Phase 2 A Revision 24 th April

Dermatology Phase 2 A Revision 24 th April 2015 Ashy Rengit The Peer Teaching Society is not liable for false or misleading information…

Topics • • Acne Eczema Psoriasis Skin ulceration – Venous, arterial, neuropathic, infective, traumatic, vasculitic • Skin cancer – Squamous cell carcinoma, basal cell carcinoma, melanoma • Infections – Cellulitis, necrotising fasciitis The Peer Teaching Society is not liable for false or misleading information…

Acne: Basic Science • Definition – Inflammation of pilosebaceous skin unit • Epidemiology – Often pubertal – Commonly (not always) ↓ with age • Pathophysiology – Bacterium • • • Staphylococcus epidermidis Pityrosporum yeast Propionibacterium acnes – Follicular hyperkeratinisation + pilosebaceous duct obstruction – Increased production + impaired flow of sebum The Peer Teaching Society is not liable for false or misleading information… http: //www. gloaesthetics. sg/images/hair_anatomy. gif

Acne: Subtypes • Acne vulgaris – Most common type (ref: clinical presentation) • Acne Rosacea – Affects mostly women aged 30+ – Red rashes on nose, cheeks, forehead & chin – Blackheads are unlikely The Peer Teaching Society is not liable for false or misleading information… http: //www. gloaesthetics. sg/images/hair_anatomy. gif

Acne: Subtypes • Acne Conglobata – Most severe subtype – Commonly found in males – Multiple interconnected large lesions (face, back, chest, upper • Acne Fulminans – Usually found in young men – Scarring (disfigurement) – Ulcers and cysts arms & thighs) The Peer Teaching Society is not liable for false or misleading information… http: //www. gloaesthetics. sg/images/hair_anatomy. gif

Acne: Subtypes • Gram-negative Folliculitis – Bacterial infection associated with longterm Acne vulgaris (antibiotic) treatment – Associated with pustules and cysts • Rosacea Fulminans – Aka Pyoderma Faciale – 20 to 40 year old females – Large, painful nodules/ pustules (scarring) – May occur without previous history of acne The Peer Teaching Society is not liable for false or misleading information… http: //www. gloaesthetics. sg/images/hair_anatomy. gif

Acne: Clinical Presentation • History – Demographic: puberty – PMH: PCOS (polycystic ovarian syndrome), Cushing’s syndrome, prolactinoma – Acute onset, skin greasy/ painful Papules Solid, raised lesion with no fluid Pustules Solid, raised lesion containing fluid or pus • Examination Blackheads Closed comedones – oxidation of melanin pigment Whiteheads Open comedones Nodules Solid, raised lesion with no fluid (larger than papules) Cysts Fluid filled sac beneath the skin The Peer Teaching Society is not liable for false or misleading information… http: //www. gloaesthetics. sg/images/hair_anatomy. gif

Acne: Management • Investigations – BLOOD • Luteinising hormone levels (↑ LH: FSH in PCOS) • Prolactin (↑ in prolactinoma) • Sex-hormone binding globulin • Testosterone • 17 -OH-progesterone (Congenital adrenal hyperplasia) – URINE • 24 hour urinary cortisol (↑ in Cushing’s syndrome) – IMAGING • Pelvic ultrasound (ovarian cysts, PCOS) • Treatment – Mild/ moderate acne • Non-greasy cosmetics/ creams • OTC benzoyl peroxide/ azelaic acid – Moderate/ severe acne • Topical antibiotic e. g. Clindamycin (blocks bacterial ribosomes) • Vit. A derivatives (retinoin) – Severe inflammatory acne OR failed topical treatment • Systemic antibiotics e. g. erythromycin or oxytetracycline – Severe acne • Oral vitamin A (isoretinoin) • SE: Teratogenic, hyperlipidaemia • Female: should take contraceptive pill or cyproterone acetate (antigonadotropin) The Peer Teaching Society is not liable for false or misleading information… http: //www. gloaesthetics. sg/images/hair_anatomy. gif

Eczema: Basic Science • Definition – Pruritic (itchy) papulovesicular (papule – solid raised lesion, vesicle – filled with fluid) skin reaction to endogenous or exogenous agents • Pathophysiology of the subtypes – Irritant eczema: prolonged skin contact with cell-damaging irritant (e. g. ammonia) – Contact eczema: Type 4 delayed hypersensitivity reaction (e. g. perfumes or latex) – Atopic eczema • Impaired epidermal barrier function due to structural abnormality (increased sensitivity) • Immune function disorder (inflammatory response to environ by Langerhans and T cells) – Seborrhoeic eczema (Pityrosporum yeast mediated) – Varicose eczema: Increased venous pressure in lower limbs The Peer Teaching Society is not liable for false or misleading information…

Eczema: Subtypes • Contact & Irritant – Often a well-localised rash – Acute inflammation – Autosensitisation possible (spread to other sites) • Atopic – Acute inflammatory rash with dry and scaly patches – Common on face and flexures (elbows and knees) The Peer Teaching Society is not liable for false or misleading information…

Eczema: Subtypes • Seborrhoeic – Yellow, greasy scales on erythematous plaques – Nasolabial folds, eyebrows, scalp and presternal area • Pompholyx – Acute and recurrent – Painful vesiculobulbous eruption – Palms and soles The Peer Teaching Society is not liable for false or misleading information…

Eczema: Subtypes • Varicose – Eczema in lower limbs – Associated with marked varicose veins – May spread to forearms • Nummular – Coin shaped rashes – On legs and trunk The Peer Teaching Society is not liable for false or misleading information…

Eczema: Subtypes • Asteatotic – Dry patterned patches – Often occurs in the elderly • History on presentation – – Severe itching Heat, tenderness, redness Occupational exposure e. g. bleach Family history of atopy e. g. asthma • Examination – Acute • Poorly demarcated dry scaly patches (red and inflamed) • Papules/ vesicles with exudation and crusting (scratch marks) – Chronic • Thickened epidermis (lichenification/ fissures) • Change in pigmentation The Peer Teaching Society is not liable for false or misleading information…

Eczema: Management • Investigations – SKIN PATCH TESTING • Contact dermatitis • Diluted allergen applied to part of skin • After 48 hours – red raised lesion – TESTING Ig. E LEVELS • Not used routinely or currently recommended – SKIN SWAB • Infected lesions • Commonly Staph. aureus, Herpes simplex (life-threatening) and Molluscum contagiosum *Eczema + Thrombocytopenia (haematological malignancy) = WISKOTT-ALDRICH SYNDROME • Treatment – Irritant or contact dermatitis • Avoid precipitant/ protection (gloves) – Atopic dermatitis Avoid precipitant Emollient creams and soaps Low potency steroids/ antihistamines Tacrolimus (calineurin inhibitor) if severe • Systemic immunosuppression/ phototherapy as a last resort • • – Seborrhoeic dermatitis • 1% hydrocortisone cream + antifungal (ketoconazole shampoo for scalp) – Pompholyx • Topical steroid (systemic if severe) • Potassium permangante salts The Peer Teaching Society is not liable for false or misleading information…

Psoriasis: Basic Science • Definition – Chronic inflammatory skin disease that is often relapsing/ remitting – May be complicated by arthritis – Can be disfiguring (psychosocial complications) • Epidemiology – Peak age of onset → 20 years • Aetiology & Pathophysiology – Unknown causes: genetic ? Environmental – strep. infections? Drugs – antimalarial agents, lithium, beta-blockers ? – Rapid cell turnover mediated by lymphocytic cytokines → Excessive proliferation of epidermal cells – Upward migration of immature keratinocytes (silver plaque appearance) The Peer Teaching Society is not liable for false or misleading information…

Psoriasis: Subtypes • Discoid/ nummular – Symetrical welldemarcated erythematous plaques – Silver scales on extensor surface (knee, elbows, scalp, sacrum) • Flexural – Less scaly plaques – Flexures (axilla, groin, perianal, genital) The Peer Teaching Society is not liable for false or misleading information…

Psoriasis: Subtypes • Guttate – Small ‘teardrop’ lesions – Trunk & limbs – Associated with Strep. (sore throat) • Palmoplantar – Erythematous plaques with pustules – Smoking, middle-aged, female, autoimmune thyroid S- ynovitis A- cne P- ustulosis H- yperostosis O- steitis The Peer Teaching Society is not liable for false or misleading information…

Psoriasis: Subtypes • Generalised Pustular – Pustules (limbs/ torso) – Hyperparathyroidism • History – Itching/ tenderness – AUSPITZ PHENOMENON • Pinpoint bleeding with removal of scales – KOEBNER PHENOMENON • Skin lesions develop at sites of trauma/ scarring The Peer Teaching Society is not liable for false or misleading information…

Psoriasis: Clinical Presentation • Nails Pitting Onycholysis Nail lifted off nailbed Subungual hyperkeratosis (salmon patch) • Joints (seronegative arthritis) – Monoarthritis – Distal asymmetrical oligoarthritis (interphalangeal) – Dactylitis (flexor tenosynovitis) – Rheumatoid arthritis-like – Arthritis mutilans – Ankylosing spondylitis The Peer Teaching Society is not liable for false or misleading information…

Psoriasis: Management • Investigations – GUTTATE • Anti-streptolysin-O-titre • Throat swab – FLEXURAL • Skin swab (Ddx: candidiasis ? ) – NAIL • Onychomyosis (fungal infections) – JOINT • Rheumatoid factor (negative) • Radiographs – distal interphalangeal joints (pencil-in-cup whittling deformity) – Sacroiliitis – Osteoporosis/ bone erosions • Treatment – GENERAL • Avoid triggers (smoking/ alcohol) – SKIN • • • Emollients + topical steroids (Eumovate) Coal tar (reduce DNA synthesis) Vit. D 3 analogue (calcipotriol) Topical retinoids PUVA (Psoratein PO + UV-A light therapy) UV-B light therapy – JOINTS • NSAIDs/ intra-articular steroid injections • Severe: methotrexate +/ ciclosporin – SYSTEMIC • Methotrexate (teratogenic) • Retinoids (pustular psoriasis, CI: pregnancy) • Anti-TNF (infliximab)/ ciclosporin trials The Peer Teaching Society is not liable for false or misleading information…

Skin Ulceration: Subtypes • Venous – Increased BP in lower limb due to poor venous return – Fluid out of veins causes swelling/damage/ breakdown – Investigation: ABPI (Ankle Brachial Pressure Index), Bloods (heart/kidney disease) and radiographs – Prevention: stop smoking, improve nutrition, compression stockings – Compression bandaging, surgery • Appearance – – Break in the skin Oedema + fibrous exudate Localised pigment loss May encircle the lower limb The Peer Teaching Society is not liable for false or misleading information…

Skin Ulceration: Subtypes • Arterial – Caused by ischaemia (reduced perfusion) – Surrounding skin becomes weak, damaged (slow repair) – Investigation: Bloods (clotting), arterial doppler scan/ pulse volume recording, radiographs (osteomyelitis) – Prevention: diabetic nutrition, stop smoking – Treatment: antibiotics if needed, surgery (debridement/ vascular bypass) • Appearance – Punched out appearance (intensely painful) – Gray or yellow fibrotic base – Pulses not palpable – Thin, shiny skin or absent hair growth (poor perfusion) The Peer Teaching Society is not liable for false or misleading information…

Skin Ulceration: Subtypes • Neuropathic e. g. DM – Altered metabolism results in slow wound healing and repair – Ulcer persists and may worsen – Investigation: Blood glucose, Doppler pressure scan, swabs (infection), radiograph / X-ray (osteomyelitis) – Prevention: glycaemic control, stop smoking, comfortable shoes (lessen pressure), debridement • Appearance – – Blisters and sores (chronic) Thickening callus formation Painless, punched out ulcers Superadded infection (cellulitis, abscess, osteomyelitis) The Peer Teaching Society is not liable for false or misleading information…

Skin Ulceration: Subtypes • Infective/ Traumatic – Often occurs in wound/ preexisting ulcer – Associated with pus, exudate formation – Investigation: Swabs, Bloods (WBC), Imaging (radiograph) – Treatment: Initially broadspectrum antibiotic, but once lab results are back – use relevant narrow-spectrum antibiotic (ANTIBIOTIC RESISTANCE) + debridement • Vasculitic – Inflammatory destruction of blood vessels leads to ischaemia and ulcer formation – Investigation: skin/ ulcer biopsy, bloods (ESR/ CRP/ WBC) – Treatment: immunosuppression (corticosteroids e. g. prednisolone/ cyclophosphamide) The Peer Teaching Society is not liable for false or misleading information…

Skin Cancer: Squamous Cell Carcinoma • Epidermal keratinocytes – Invade dermis and metastasise – Often found on sun exposed areas (hyperkeratotic – crusty) • Risk factors – – – Sunlight exposure (light skin) Radiation Carcinogens e. g. smoking Chronic skin disease HPV Longterm immunosuppression (middle aged) • Investigations – Skin biopsy (gold standard) – Fine-needle aspirate/ lymph node biopsy (metastasis ? ) – Staging (CT/MRI/PET scan) • Treatment Surgical excision Mohs micrographic surgery Sentinel lymph node biopsy Local radiotherapy/ chemoherapy in metastasis – Intra-lesional interferons (topical 5 fluoracil) – – The Peer Teaching Society is not liable for false or misleading information…

Skin Cancer: Squamous Cell Carcinoma The Peer Teaching Society is not liable for false or misleading information…

Skin Cancer: Basal Cell Carcinoma • Commonest form (rodent ulcer) • Basal cells invade dermis and metastasise (slow) • Risk factors – Prolonged sun exposure (light skin) – UV radiation – Elderly • Examination – Ill-defined nodulo-ulcerative – Telangiectasia – Superficial and pigmented • Investigations – Biopsy rarely needed • Treatment – Surgical excision – Radiotherapy The Peer Teaching Society is not liable for false or misleading information…

Skin Cancer: Basal Cell Carcinoma The Peer Teaching Society is not liable for false or misleading information…

Skin Cancer: Melanoma • Neoplastic transformation of melanocytes (pigment forming cells) • Life threatening • • • A - symetry B – order irregularity/ bleed C – olour variation D – iameter. 6 mm E – levation of lesion • Investigations – Excisional biopsy – Lymphoscintigraphy (drainage) – Sentinal lymph node biopsy – Staging (CT/ MRI/ PET scan) – Blood: LFT (metastasis) • Treatment – – Prevention: avoid sunburn Wide local surgical excision Chemotherapy (cisplatin) Biological therapy (interferon) The Peer Teaching Society is not liable for false or misleading information…

Skin Cancer: Melanoma The Peer Teaching Society is not liable for false or misleading information…

Infections: Cellulitis • Acute non-prurulent spreading infection of subcutaneous tissue • Overlying skin inflammation • Periorbital: swollen eyelid • Orbital: proptosis, impaired acuity and eye movement ! • Often results from penetrating injury, lesions, fissuring – Strep. pyogenes – Staph. aureus (especially MRSA) – H. influenza (especially in the orbit) • Investigation – – Bloods (WBC, Blood cultures) Discharge (culture, sensitivity) Aspiration, if prurulent CT/MRI scan (orbital cellulitis) • Treatment – Benzylpenicillin/ tetracycline – Orbital decompression – Aspiration/ drainage of abscess – Monitor optic nerve function The Peer Teaching Society is not liable for false or misleading information…

Infections: Cellulitis The Peer Teaching Society is not liable for false or misleading information…

Infections: Necrotising Fasciitis • Acute infection of deeper subcutaneous tissue layers – Bacterium release toxins which destroy skin/ muscle tissue • Can be caused by – Strep. pyogenes – Staph. Aureus (MRSA) – Clostridium perfringens’ • Suspect if – Pain reported is greater than appearance of skin – Inflammation, fever, tachycardia, D&V – Quick discoloration to violet/ skin swelling (blister necrosis) • EMERGENCY TREATMENT • Investigations – Bloods (CRP/ WBC/ Hb/ Na+/ Creatinine/ Glucose) – Presumptive – Broad spectrum antibiotics – Aggressive surgical debridement The Peer Teaching Society is not liable for false or misleading information…

Infections: Necrotising Fasciitis The Peer Teaching Society is not liable for false or misleading information…

Brief: 2° skin disorders • Skin manifestations of other disorders HIV/AIDs (Kaposi sarcoma – red/violet/blue/black macules – nodules) Tropical diseases (variable e. g. blisters) Amyloidosis (deposition of hyperpigmented macules) Breast disease • Fibroadenoma (painless, firm, solitary and mobile lump) • Cysts (smooth, easily mobile, but tender lump with variable size) • Intraductal papilloma (small, painful lump + nipple discharge) • Breast cancer (lump + puckering/ dimpling skin + inverted nipple) – Lymphoedema • Primary (filiariasis – red, itchy swelling & migrating worm seen) • Secondary (post-irradiation therapy – skin reaction or bruising) – – The Peer Teaching Society is not liable for false or misleading information…

Dermatology: Phase 2 Exams • May form a large part of the marks (SAQ – Cellulitis) • Part of questions involving systemic disorders • Terminology and epidemiology is important (SBA – identifying disease) • One disease, many presentations – Usually most common diseases/ presentations The Peer Teaching Society is not liable for false or misleading information…

Additional Revision Resources • http: //www. dermnetnz. org/ • http: //library. med. utah. edu/kw/derm/Derm. Quiz/ • https: //itunes. apple. com/gb/app/dermatology-medicalstudent/id 670207116? mt=8 • https: //play. google. com/store/apps/details? id=com. multipie. dermatology • Books – Oxford Handbook of Clinical Specialties – Rapid Medicine – Lecture Notes Dermatology The Peer Teaching Society is not liable for false or misleading information…