Dermatology Flashcards
What is classified as moderate acne
Widespread non-inflammatory lesions and numerous papules and pustules
What is classified as severe acne
Extensive inflammatory lesions, which may include nodules, pitting, and scarring
First line treatment for mild to moderate acne
12 week course of topical combination therapy:
- Fixed combo topical tretinoin with topical clinda
- Fixed combo topical benzoyl peroxide with topical clinda or topical adapalene
When can topical benozyl peroxide be used as monotherapy?
If combo contraindicated, or person wishes to avoid using topical retinoid or an antibiotic
First line treatment for moderate to severe acne
12 week course of:
- Fixed combo topical adapalene with topical benzoyl peroxide (+/- oral lymecycline or oral doxy)
- Fixed combo topical tretinoin with topical clinda
- Topical azelaic acid + oral lymecycline/doxy
What antibiotic used for acne in pregnancy/breastfeeding?
Erythromycin
Why is minocycline not used in acne anymore
Possibility of irreversible pigmentation
How long can you continue acne treatment including antibiotic (topical or oral)
6 months unless exceptional circumstances
Can antibiotics be used as monotherapy?
No, always co-prescribe topical retinoid or benozyl peroxide to avoid antibiotic resistance
Complication of long term antibiotic use in acne
Gram negative folliculitis
Treatment for gram negative folliculitis occurring as complication from long term abx use in acne
High dose oral trimethoprim
Role of COCP in acne
Can be used as alternative to PO Abx in women
Should be used in combination with topical agents
What COCP useful in acne
Dianette (co-cyprindiol)
Advantage of dianette in acne
Anti-androgen properties
Limitation of dianette in acne
Increased risk of VTE compared to other COCP, so should generally only be used second line, only for 3 months, and with counselling
Role of oral isotretinoin in acne
Only under specialist supervision
Definite referral criteria acne
- Conglobate acne
- Nodulo-cystic acne
What is conglobate acne?
Rare and severe form, mostly in men, extensive inflammaotry papules, suppurative nodules that may coalesce to form sinuses, cysts on trunk
When to consider referral for acne
- Mild to moderate acne not responding to two completed courses of treatment
- Moderate to severe acne not responded to treatment including oral antibiotic
- Acne with scarring
- Acne with persistent pigmentary changes
- Acne causing distress or contributing to persistent psychological distress or mental health disorder
What is erythema nodosum
Inflammation of SC fat, typically causing tender, erythematous, nodular lesions
Causes of erythema nodosum
Infection
Systemic disease
Malignancy/lymphoma
Drugs
Pregnancy
Infections causing erythema nodosum
Streptococci
Tuberculosis
Brucellosis
Systemic disease causing erythema nodosum
Sarcoidosis
Inflammatory bowel disease
Behcet’s
Drugs causing erythema nodosum
Penicillins
Sulphonamides
COCP
First line treatment chronic plaque psorasis
Potent corticosteroid OD + vitamin D analogue OD, up to 4 weeks as initial treatment
Applied seperately, one in morning one in evening
Second line treatment chronic plaque psoriasis
Vitamin D analogue BD
Third line treatment chronic plaque psorasis
Potent corticosteroid BD (up to 4 weeks), or coal tar OD-BD
Other treatment options in primary care chronic plaque psoriasis
Short-acting dithranol
Secondary care management options chronic plaque psoriasis
- Phototherapy
- Photochemotherapy
- Systemic therapy
What kind of phototherapy given in chronic plaque psorasis
Narrowband UVB light, if poss 3 times a week
What kind of photochemotherapy chronic plaque psoriasis
Psoralen and UVA light (PUVA)
Adverse effects of phototherapy in chronic plaque psoriasis
Skin ageing
Squamous cell carcinoma
Systemic therapies used in chronic plaque psoriasis
Methotrexate (first line)
Ciclosporin
Systemic retinoids
Biological agents - infliximab, etanercept, adalimumab
First line treatment scalp psorasis
Potent topical corticosteroids OD for 4 weeks
Second line treatment scalp psoriasis
Alternative preparation of potent corticosteroid, e.g. shampoo or mousse, and/or topical agents to remove adherent scale (e.g. agents containing salicyclic acid, emollients, oils) before application of potent corticosteroid
Treatment for face, flexural, and genital psoriasis
Mild to moderate potency corticosteroid applied OD-BD max 2 weeks
SEs topical steroids
Skin strophy
Striae
Rebound symptoms
Examples of vitamin D analogues
Calcipotriol
Calcitriol
Tacalcitol
Advantages of vit D analogues
Adverse effects uncommon
Unlike corticosteroids can be used long term
Unlike coal toar and dithranol do not smell or stain
Disadvantage of vit D analogues
Tend to reduce scale and thickness of plaques but not erythema
Avoid in pregnancy
Adverse effects of dithranol
Burning and staining (wash off after 30 mins)M
Mild potency corticosteroid e.g.
HydrocortisoneM
Moderate potency corticosteroid e.g.
Clobetasone
Alclometasone
Hydrocortisone butyrate
Potent corticosteroid e.g.
Beclometasone
Betamethasone
Fluticasone
Mometasone
Very potent corticosteroid e.g.
Clobetasol
Appearance of actinic ketatoses
Small, crusty or scaly
Pink, red, brown, or same colour as skin
Rule of 9’s for burns
Each 9% SA:
- Head and neck
- Each arm
- Each anterior part of leg
- Each posterior part of leg
- Anterior chest
- Posterior chest
- Anterior abdomen
- Posterior abdomen
Criteria for referral to secondary care burns
- All deep dermal and full thickness burns
- Superficial dermal burns of more than 3% TBSA adults, 2% in children
- Superficial dermal burns involving face, hands, feet, perineum, genitalia, any flexure, circumferential burns limbs, torso, or neck
- Inhalation injury
- Electrical or chemical burn
- Suspicion of NAI
When are IV fluids required burns
Over 10% TBSA children, 15% in adults
Parkland formula
Volume of fluid = TBSA burn x weight (kg) x 4
Half fluid given in first 8 hours (from time of burn)
What is erythema multiforme
Hypersensitivity reaction
Features of erythema multiforme
- Target lesions
- Initially seen on back of hands/feet before spreading to torso
- Upper limbs > lower limbs
Causes of erythema multiforme
- Viruses
- Idiopathic
- Bacteria
- Drugs
- Connective tissue disease
- Sarcoidosis
- Malignancy
Most common cause of erythema multiforme
Herpes simplex virus
Bacteria causing eythema multiforme
Mycoplasma
Streptococcus
Drugs causing erythema multiforme
Penicillin
Sulphonamides
Carbamazepine
Allopurinol
NSAIDs
OCP
Nevirapine
What is erythema multiforme major
More severe form, with mucosal involvement
Causes of hypertrichosis
Drugs
Congenital
Porphyria cutanea tarda
Anorexia nervosa
Drugs causing hypertrichosis
Minoxidil
Ciclosporin
Diazoxide
Causative organisms impetigo
Staph aureus
Strep pyogenes
First line treatment for limited, localised impetigo
Hydrogen peroxide 1%
Other treatment options for limited, localised impetigo
- Topical fusidic acid
- Topical mupirocin (if fusidic acid resistance suspected or MSRA)
Treatment for extensive impetigo
Oral fluclox
Oral erythromycin if pen allergic
Features of lichen planus
Itchy, papular rash most common on palms, soles, genitalia, flexor surfaces of arms
Often polygonal in shape, with ‘white lines’ pattern on surface
Koebner phenomenon may be seen
Oral involvement in 50% of patients - white lace pattern on buccal mucosa
Nail changes in lichen planus
Thinning of nail plate
Longitudinal ridging
Causes of lichenoid drug eruptions
Gold
Quinine
Thiazides
What is lichen sclerosus
Inflammatory condition, usually affecting genitalia, leading to atrophy of epidermis with white plaques forming
Demographic lichen sclerosus
Elderly females
Features of lichen sclerosus
- White patches that may scar
- Itch prominent
- May result in pain during intercourse or urinary
What is livedo reticularis?
Purplish, non-blanching, reticulated rash caused by obstruction of the capillaries resulting in swollen venules
Causes of livedo reticularis
- Idiopathic (most common)
- Polyarteritis nodosa
- Systemic lupus erythematosus
- Cryoglobulinaemia
- Antiphospholipid syndrome
- Ethlers-Danlos syndrome
- Homocystinuria
What is pemphigus vulgaris
Autoimmune disease cause by antibodies directed against desmoglein 3
Pemphigus vulgaris demographic
More common in Ashkenai Jewish
Features of pemphigus vulgaris
Mucosal ulceration common, seen in 50-70%
Flaccid, easily ruptured vesicles and bullae, painful
Nikolsky’s sign
What is Nikolsky’s sign
Spread of bullae following application of horizontal, tangential pressure to the skin
Treatment of pemphigus vulgaris
Steroids first line
Immunosuppressants
Cause of pityriasis rosea
Not fully understood, HHV-7 may play role
Features of pityriasis rosea
Herald patch, usually on trunk
Followed by erythematous, oval, scaly patches following characteristic distribution with longitudinal diameters of oval lesions running paralllel to the line of Langer, may produce fir tree appearance
Cause of pityriasis versicolor
Superficial cutaneous fungal infection caused by Malassezia furfur
Features of pityriasis versicolor
Most commonly affects trunk
Patches may be hypopigmented, pink, or brown
Scale common
Mild pruritis
Predisposing factors pityriasis versicolor
Immunosuppression
Malnutrition
Cushing’s
What is pyoderma gangrenosum
Neutrophilic dermatosis causing very painful skin ulcerationM
Site of pyoderma gangrenosum
May affect any part of skin, but lower legs most commonE
Causes of pyoderma gangrenosum
- Idiopathic (50%)
- Inflammatory bowel disease
- Rheumatological
- Haematological
- Granulomatosis with polyangiitis
- Primary biliary cirrhosis
Rheumatological causes of pyoderma gangrenosum
Rheumatoid arthritis
SLE
Haematological causes of pyoderma gangrenosum
Myeloproliferative disorders
Lymhoma
Myeloid leukaemia
Monoclonal gammopathy
Features of pyoderma gangrenous
Starts quite suddenly as small pustule, red bump, or blood blister
Skin then breaks down resulting in ulcer, edge purple, violaceous and undermined. Ulcer itself deep and necrotic.
May have systemic symptoms e.g. fever, myalgiaW
Features of pyogenic granuloma
Initially small red/brown spot, rapidly progresses to raised, red/brown lesions spherical in shape, may bleed profusely or ulcerate
Risk factors for pyogenic granuloma
- Trauma
- Pregnancy
- Women/young adults
Treatment for rosacea with predominant flushing but limited telangiectasia
Topical brimonidine gel
First line treatment for rosacea with mild to moderate papules and/or pustules
Topical ivermectin
Alternative treatment for rosacea with mild to moderate papules and/or pustules
Topical metronidazole
Topical azelaic acid
Treatment for rosacea with moderate to severe papules/pustules
Combination of topical ivermectin and oral doxycycline
When to refer in rosacea
If symptoms not improved with optimal management in primary care
Patients with rhinophyma
First line treatment scabies
Permethrin
Second line treatment scabies
Malathion
Features of seborrheoic keratosis
‘Stuck on’ appearance
Keratotic plugs may be seen on surface
What is pretibial myxodema
Symmetrical, erythematous lesions, causing shiny orange peel skin
What is pretibial myxodema seen in
Graves disease
What is necrobiosis lipoidica diabecticorum
Shiny, painless areas of yellow/red skin typically on shin of diabetics
Analgesia in shingles
Paracetamol and NSAIDs first line
If not responding, neuropathic agents e.g. amitriptryline
Role of steroids in shingles
Can be considered in first 2 weeks in immunocompetent adults with localised shingles if pain is severe and not responding to other analgesics
Role of anti-virals in shingles
Antivirals if within 72 hours (unless <50 years and ‘mild’ truncal rash with mild pain and no underlying risk factors)
What malignancy is acanthosis nigricans associated with
Gastric cancer
What malignancy is acquired ichthyosis associated with
Lymphoma
What malignancy is acquired hypertrichosis lanuginosa associated with
GI and lung cancer
What malignancy is dermatomyositis associated with
Ovarian and lung cancer
What malignancy is erythema gyratum repens associated with
Lung cancer
What malignancy is erythroderma associated with
Lymphoma
What malignancy is migratory thrombophlebitis associated with
Pancreatic cancer
What malignancy is necrolytic migratory erythema associated with
Glucagonoma
What malignancy is pyoderma gangrenosum associated with
Myeloproliferative disorders
What malignancy is Sweet’s syndrome associated with
Haematological malignancy, e.g. myelodysplasia
What malignancy is tylosis associated with
Oesophageal cancer
What is tylosis
Hyperkeratosis of palms and soles, with thickening and fissuring of the skin
Most common skin condition associated with pregnancy
Atopic eruption of pregnancy
Features of atopic eruption of pregnancy
Eczematous, itchy red rash
Features of polymorphic eruption of pregnancy
Pruritic, lesions often first appear in abdominal striae, associated with last trimester
Features of pemphigoid gestationis
Pruritic blistering lesions
Often develop in peri-umbilical region, later spreading to trunk, back, buttocks, and arms
When does pemphigoid gestationis present?
2nd or 3rd trimester
Rarely seen in first pregnancy
Causes of Stevens-Johnson syndrome
- Pencillins
- Sulphonamides
- Lamotrigine
- Carbamazepine
- Phenytoin
- Allopurinol
- NSAIDs
- OCP
Features of SJS rash
Maculopapular with target lesions, may develop into vesicles or bullae
Nikolsky sign positive in erythematous areas
Mucosal involvement
Systemic symptoms - fever, arthralgia
Causes of spider naevi
Liver disease
Pregnancy
COCP
Spider naevi vs telangiectasia
Press and watch fill - spider naevi fill from centre, telangiectasia from edge
What is toxic epidermal necrolysis
Potentially life threatening skin disorder commonly seen secondary to drug reaction
Features of toxic epidermal necrolysis
Skin develops scalded appearance over extensive area
Systemically unwell - pyrexia, tachycardia
Positive Nikolsky’s sign
Drugs causing TEN
- Phenytoin
- Sulphonamides
- Allopurinol
- Penicillins
- Carbamazepine
- NSAIDs
Treatment for SJS
- Stop precipitant
- Supportive care
- IV immunoglobulin
- Immunosuppressive agents (ciclosporin and cyclophosphamide), plasmapheresis
Treatment of venous ulceration
Compression bandaging, usually four layer (only treatment shown to be of benefit)
Features of zinc deficiency
Acrodermatitis
Alopecia
Short stature
Hypogonadism
Hepatosplenomegaly
Geophagia (ingesting clay/soil)
Cognitive impairment
Features of acrodermatitis caused by zinc deficiency
- Red crusted lesions
- Acral distribution - peri orificial
