Dermatology Flashcards
Rosacea features?
- Nose, cheeks, forehead
- Flushing, telangiectasia
- Develops into persistent erythema with papules and pustules
- Rhinophyma
- Ocular involvement = blepahritis
- Sunlight may exacerbate features
Rosacea Rx?
- Topical metronidazole for mild symptoms
- Topical brimonidine gel with predominant flushing but limited telangiectasia
- Oral oxytetracycline for more severe disaese
- Sunscreen, camouflage cream, laser therapy if prominent telangiectasia
- Rhinopyma –> referred to dermatology
Bullous pemphigoid definition?
An autoimmune condition causing sub-epidermal blistering of the skin
Bullous pemphigoid pathophysiology?
Development of antibodies against hemidesmosomal proteins BP180 and BP230
Bullous pemphigoid features?
- Itchy, tense blisters around flexures
- Blisters heal without scarring
- No mucosal involvement
Bullous pemphigoid biopsy?
Immunofluorescence shows IgG and C3 at dermo-epidermal junction
Bullous pemphigoid Rx?
- Referral to dermatology for biopsy and confirmation of Dc
- Oral corticosteroids
- Topical corticosteroids, immunosuppressants and Abx are also used
Seborrhoeic keratosis features?
- Large variation in colour from flesh to light-brown to black
- Have a stuck-on appearance
- Keratotic plugs may be seen on the surface
Seborrhoeic keratosis Rx?
- Reassurance
- Removal = curettage, cryosurgery, shave biopsy
Shingles definition?
Acute, unilateral, painful blistering rash caused by reactivation of the varicella-zoster virus (VZV). Following primary infection with VZV (chickenpox), the virus lies dormant in the dorsal root or cranial nerve ganglia
Shingles RFs?
- Age
- HIV: x15
- Immunsuppression
Most commonly affected shingle dermatomes?
T1-L2
Shingles features?
- Prodromal period = burning pain over dermatome for 2-3 days, may interfere with sleep, 20% will experience fever/headache/lethargy
- Rash = erythematous and macular, becomes vesicular, well demarcated by dermatome and doesnt cross midline, bleeding into adjacent areas may be seen
Shingles Dx?
Clinical
Shingles Rx?
- Potentially infectious = avoid pregnant and immunosuppressed, infectious until vesicles crusted over, 5-7 days following onset, covering lesions reduces risk
- Analgesia = Paracetamol and NSAIDs, neuropathic agents, oral corticosteroids may be considered in the first 2 weeks in immunocompetent adults with localized shingles if the pain is severe and not responding to the above treatments
- Antivirals = within 72h, unless unless the patient is < 50 years and has a ‘mild’ truncal rash associated with mild pain and no underlying risk factors. Reduced incidence of post-herpetic neuralgia. Aciclovir/famciclovir/valaciclovir
Shingles complications?
- Post-herpetic neuralgia = most common, 5-30%, usually resolves within 6 months
- Herpes zoster ophthalmicus
- Herpes zoster oticus (Ramsay-Hunt syndrome)
Eczema herpeticum mushkies?
Severe primary infection of the skin by HSV 1/2. On examination, monomorphic punched-out erosions (circular, depressed, ulcerated lesions) usually 1–3 mm in diameter are typically seen. Rx = IV aciclovir as is potentially life threatening
Toxic epidermal necrolysis (TEN) definition?
A potentially life-threatening skin disorder that is most commonly seen secondary to a drug reaction. In this condition, the skin develops a scalded appearance over an extensive area. Some authors consider TEN to be the severe end of a spectrum of skin disorders which includes erythema multiforme and Stevens-Johnson syndrome
TEN features?
- Systemically unwell e.g. pyrexia, tachycardia
- Positive Nikolsky’s sign = epidermis separates with mild lateral pressure
Drugs known to induce TEN?
- Phenytoin, Penicillins
- Sulphonamides
- Allopurinol
- Carbamazepine
- NSAIDs
TEN Rx?
- Stop precipitating factor
- Supportive care = ITU
- IVIG 1st line
- Others = immunosuppressive agents (ciclosporin and cyclophosphamide), plasmapharesis
Chondrodermatitis nodularis helicis definition?
A common and benign condition characterised by the development of a painful nodule on the ear. It is thought to be caused by factors such as persistent pressure on the ear (e.g. secondary to sleep, headsets), trauma or cold. CNH is more common in men and with increasing age.
Chondrodermatitis nodularis helicis Rx?
- Reducing pressure on ears = foam protectors
- Cryotherapy, steroid injection, collagen injection
- Surgery possible but high recurrence rate
Lichen planus features?
- Itchy, papular rash on palms, soles, genitalia and flexor surfaces of arms
- Rash often polygonal, white lines on surface (Wickham’s striae)
- Koebner phenomenon
- Oral involvement on 50%
- Nails = thinning of nail plate, longitudinal ridging
Lichenoid drug eruption causes?
- Gold
- Quinine
- Thiazides
Lichen planus Rx?
- Potent topical steroids
- Benzydamine mouthwash or spray for oral
- If extensive may require oral steroids or immunosuppression
Chronic plaque psoriasis Rx?
Regular emollients
1. 1st line = Potent corticosteroid OD + Vitamin D analogue OD, apply separately one in AM and one in PM, for up to 4 weeks as initial treatment
2. 2nd line = If no improvement after 8 weeks, Vitamin D analogue BD
3. 3rd line = If no improvement after 8-12 weeks, Potent corticosteroid BD up to 4 weeks or coal tar OD/BD
4. Short acting dithranol can also be used
Psoriasis secondary care management?
- Phototherapy
- Systemic therapy
Psoriasis phototherapy mushkies?
- Narrowband UVB 3x week preferred
- Photochemotherapy (PUVA)
Phototherapy s/e?
Skin ageing, SCC (not melanoma)
Psoriasis systemic therapies?
- Oral MTX 1st line
- Ciclosporin
- Systemic retinoids
- Biological = Infliximab, Etanercept, Adalimumab
- Ustekinumab (IL12 & IL23) showing promise
Scalp psoriasis Rx?
- Potent topical corticosteroid OD 4 weeks
- If no improvement after 4 weeks –> use different formulation of the potent corticosteroid (for example, a shampoo or mousse) and/or a topical agents to remove adherent scale (for example, agents containing salicylic acid, emollients and oils) before application of the potent corticosteroid
Face, flexural and genital psoriasis Rx?
Mild/moderate potency corticosteroid OD/BD for maximum 2 weeks
Topical steroids psoriasis mushkies?
- S/e = skin atrophy, striae, rebound symptoms
- Don’t treat scalp, face and flexures for more than 1-2 weeks per month
- Systemic s/e seen when used >10% BSA
- 4 week break before starting another course of topical corticosteroids
- Potent corticosteroids for no longer than 8 weeks at a time, very potent corticosteroids for no longer than 4 weeks at a time
Psoriasis Vitamin D analogue mushkies?
- Calcipotriol (Dovonex), calcitriol, tacalcitol
- Reduce cell division and differentiation, reducing epidermal proliferation
- Adverse effects are uncommon
- Can be used long term, do not smell or stain
- Avoid in pregnancy
- Maximum weekly amount for adults is 100g
- Tend to reduce the scale and thickness of plaques but not the erythema
Dithranol mushkies?
Inhibits DNA synthesis, wash off after 30 mins, s/e = burning, staining
Coal Tar MOA?
Probably inhibits DNA synthesis
Venous ulceration typically seen where?
Above medial malleolus
Venous ulceration Ix?
ABPI (Normal 0.9-1.2). Values below 0.9 indicate arterial disease. Interestingly, values above 1.3 may also indicate arterial disease, in the form of false-negative results secondary to arterial calcification (e.g. In diabetics)
Venous ulceration Rx?
- 4 layer compression banding (only treatment shown to be of real benefit)
- Oral pentoxifylline (peripheral vasodilator), improves healing rate
- Flavinoids
- Little evidence for hydrocolloid dressings, topical growth factors, ultrasound therapy and intermittent pneumatic compression
Dermatitis herpetiformis definition?
Autoimmune blistering skin disorder associated with coeliac disease
Dermatitis herpetiformis pathophysiology?
Deposition of IgA in the dermis
Dermatitis herpetiformis features?
Itchy, vesicular skin lesions on the extensor surfaces (e.g. elbows, knees, buttocks)
Dermatitis herpetiformis Dx?
Skin biopsy = direct immunofluorescence shows deposition of IgA in a granular pattern in the upper dermis
Dermatitis herpetiformis Rx?
- Gluten-free diet
- Dapsone
2 main types of contact dermatitis?
- Irritant
- Allergic
Irritant contact dermatitis mushkies?
Common non-allergic reaction due to weak acids or alkalis (e.g. detergents). Often seen on the hands. Erythema is typical, crusting and vesicles are rare
Allergic contact dermatitis mushkies?
Type IV hypersensitivity reaction. Uncommon - often seen on the head following hair dyes. Presents as an acute weeping eczema which predominately affects the margins of the hairline rather than the hairy scalp itself. Topical treatment with a potent steroid is indicated
Frequent cause of contact dermatitis?
Cement. The alkaline nature of cement may cause an irritant contact dermatitis whilst the dichromates in cement also can cause an allergic contact dermatitis.
Sparing of nasolabial folds?
SLE
Milia?
Small, benign, keratin-filled cysts that typically appear around the face. They may appear at any age but are more common in newborns.
Strawberry naevus AKA?
Capillary haemangioma
Strawberry naevus/capillay haemangioma features?
- Not present at birth but may grow rapidly in 1st month of life
- Erythematous, raised, multilobed tumours
- Typically they increase in size until around 6-9 months before regressing over the next few years (around 95% resolve before 10 years of age).
- Common sites include the face, scalp and back. Rarely they may be present in the upper respiratory tract leading to potential airway obstruction
- Capillary haemangiomas are present in around 10% of white infants. Female infants, premature infants and those of mothers who have undergone chorionic villous sampling are more likely to be affected
Capillary haemangioma potential complications?
- Mechanical = obstructing visual fields or airway
- Bleeding
- Ulceration
- Thrombocytopenia
Capillary haemangioma Rx?
If treatment is required (e.g. Visual field obstruction) then propranolol is increasingly replacing systemic steroids as the treatment of choice. Topical beta-blockers such as timolol are also sometimes used.
What is a cavernous haemangioma?
Deep capillary haemangioma
Acute onset tear-drop scaly papules on trunk and lumbs?
Guttate psoriasis
Guttate psoriasis features?
- More common in children and adolescents
- May be precipitated by streptococcal infection 2-4 weeks prior to lesions appearing
- Tear drop papules on the trunk and limbs, pink/scaly patches or plaques of psoriasis
- Tends to be acute onset over days
Guttate psoriasis Rx?
- Usually resolve spontaneously within 2-3 months
- No evidence for Abx
- Topical agents as per psoriasis
- UVB phototherapy
- Tonsillectomy may be necessary with recurrent episodes
Guttate psoriasis needs to be differentiated from?
Pityriasis rosea
Pityriasis rosea mushkies?
- Many patients report recent respiratory tract infections but this is not common in questions
- Herald patch followed 1-2 weeks later by multiple erythematous, slightly raised oval lesions with a fine scale confined to the outer aspects of the lesions.May follow a characteristic distribution with the longitudinal diameters of the oval lesions running parallel to the line of Langer. This may produce a ‘fir-tree’ appearance
- Self-limiting, resolves after around 6 weeks
Vitiligo definition?
Autoimmune condition which results in the loss of melanocytes and consequent depigmentation of the skin
Vitiligo epidemiology?
1% of the population and symptoms typically develop by the age of 20-30 years.
Vitiligo features?
- Well demarcated patches of depigmented skin
- Peripheries tend to be most affected
- Koebner phenomenon
Vitiligo associated conditions?
- T1DM
- Addison’s
- Thyroid
- Pernicious anaemia
- Alopecia areata
Vitiligo Rx?
- Sunblock
- Camouflage make-up
- Topical corticosteroids may reverse the changes if applied early
- May also be a role for topical tacrolimus and phototherapy, although caution needs to be exercised with light-skinned patients
Purpura definition?
Bleeding into the skin from small blood vessels that produces a non-blanching rash. Smaller petechiae (1-2 mm in diameter) may also be seen. It is typically caused by low platelets but may also be seen with bleeding disorders, such as von Willebrand disease.
Purpura definition?
Bleeding into the skin from small blood vessels that produces a non-blanching rash. Smaller petechiae (1-2 mm in diameter) may also be seen. It is typically caused by low platelets but may also be seen with bleeding disorders, such as von Willebrand disease.
Purpura definition?
Bleeding into the skin from small blood vessels that produces a non-blanching rash. Smaller petechiae (1-2 mm in diameter) may also be seen. It is typically caused by low platelets but may also be seen with bleeding disorders, such as von Willebrand disease.
Molluscum contagiosum transmission?
Closer personal contact, fomites
Molluscum contagiosum epidemiology?
Maximum incidence 1-4 y/o
Molluscum contagiosum features?
- Pinkish/pearly white papules with central umbilication, up to 5mm in diameter
- Do not occur on palms or soles
Molluscum contagiosum self care advice?
- Self limiting, within 18m
- Avoid sharing towels etc., do not scratch lesions
- No exclusion from school/gym/swimming necessary
Molluscum contagiosum Rx?
- Not usually recommended, if lesions troublesome use simple trauma or cryotherapy
- Squeezing with fingernails or piercing with orange stick following a batch
- Cryotherapy in older children or adults
- Eczema can develop around lesion –> 1% hydrocortisone if itching problematic, fusidic acid 2% if skin looks infected
Molluscum contagiosum and HIV +ve?
Urgent referral to HIV specialist
Molluscum contagiosum on eyelid margin/ocular lesions/red eye Rx?
Urgent referral to ophthalmologist
Anogenital Molluscum contagiosum in adults Rx?
Refer to GUM for screening for other STIs
Allergic contact dermatitis Ix?
Patch testing
Seborrheoic dermatitis definition?
A chronic dermatitis thought to be caused by an inflammatory reaction related to a proliferation of a normal skin inhabitant, a fungus called Malassezia furfur (formerly known as Pityrosporum ovale). It is common, affecting around 2% of the general population.
Seborrhoeic dermatitis in adults features?
- Eczematous lesions on sebum-rich areas: scalp, periorbital, auricular and nasolabial folds
- Otitis externa and blepharitis may develop
Seborrhoeic dermatitis associated conditions?
- HIV
- Parkinsons
Seborrhoeic dermatitis scalp disease Rx?
- OTC containing zinc pyrithione (H&S) and tar (Neutrogena T/gel) 1st line
- Ketoconazole 2nd line
- Selenium sulphide and topical corticosteroid may also be useful
Seborrhoeic dermatitis face and body Rx?
- Topical antifungals = ketoconazole
- Topical steroids = short periods
- Difficult to treat = recurrences are common
Scabies cause?
Sarcoptes scabiei
Scabies pathophysiology?
The scabies mite burrows into the skin, laying its eggs in the stratum corneum. The intense pruritus associated with scabies is due to a delayed-type IV hypersensitivity reaction to mites/eggs which occurs about 30 days after the initial infection.
Scabies features?
- Widespread pruritis
- Linear burrows on the side of fingers, interdigital webs and flexor aspects of the wrist
- In infants, the face and scalp may also be affected
- Secondary features are seen due to scratching: excoriation, infection
Scabies Rx?
- Permethrin 1st line
- Malathion 0.5% 2nd line
- All household/close physical contacts should be treated at the same time, even if asymptomatic
- Launder, iron or tumble dry clothing, bedding, towels, etc., on the first day of treatment to kill off mites.
How long can pruritis persist after scabies Rx?
Up to 4-6 weeks post eradication
Permethrin application isntructions?
- Apply to cool, dry skin
- Pay close attention to areas between fingers and toes, under nails, armpit area, creases of the skin such as at the wrist and elbow
- Allow to dry and leave on the skin for 8-12 hours for permethrin, or for 24 hours for malathion, before washing off
- Reapply if insecticide is removed during the treatment period, e.g. If wash hands, change nappy, etc
- Repeat treatment 7 days later
Crusted (Norwegian) Scabies?
- Seen in patients with suppressed immunity, especially HIV
- Will have hundreds of thousands of organisms
- Ivermectin is the Rx of choice and isolation is essential
Hirsutism definition?
Androgen-dependent hair growth in women
Hypertrichosis definition?
Androgen-independent hair growth
Causes of hirsutism?
- PCOS, Cushings, CAH, Androgen therapy
- Obesity, adrenal tumour, androgen secreting ovarian tumour
- Drugs = phenytoin, corticosteroids
Assessment of hirsutism?
Ferriman-Gallwey scoring system = 9 body areas are assigned a score of 0 - 4, a score > 15 is considered to indicate moderate or severe hirsutism
Hirsutism Rx?
- Weight loss if overweight
- Waxing/bleaching not available on NHS
- COCP e.g. co-cyprindiol (Dianette) or ethinylestradiol and drospirenone (Yasmin)
- Facial hirsutism = topical eflornithine - contraindicated in pregnancy and breast-feeding
Causes of hypertrichosis?
- Drugs = minoxidil, ciclosporin, diazoxide
- Congenital hypertrichosis lanuginosa, congenital hypertrichosis terminalis
- Porphyria Cutanea Tarda
- Anorexia Nervosa
Acne vulgaris pathophysiology?
Obstruction of the pilosebaceous follicles with keratin plugs which results in comedones, inflammation and pustules
Acne classification?
- Mild = open and closed comedones with or without sparse inflammatory lesions
- Moderate = widespread non-inflammatory lesions and numerous papules and pustules
- Severe = extensive inflammatory lesions, which may include nodules, pitting, and scarring
Acne Rx?
- Single topical therapy = topical retinoids, benzoyl peroxide
- Topical combination therapy
- Oral Abx
- COCP
- Oral isotretinoin
Acne oral Abx mushkies?
- Tetracycline = lymecycline, doxycycline, oxytetracycline
- Avoid tetracyclines in pregnant/breastfeeding/children<12y/o
- Use erythromycin in pregnancy
- Single oral abx should be used for maximum of 3m
- Topical retinoid (if not contraindicated) or benzoyl peroxide should always be co-prescribed with oral antibiotics to reduce the risk of antibiotic resistance developing
- Gram-negative folliculitis may occur as a complication of long-term antibiotic use - high-dose oral trimethoprim is effective if this occurs
Topical and oral Abx in combination?
No
Gram -ve folliculitis Rx?
High dose oral trimethoprim
Acne COCP Rx mushkies?
- Use in combination with topical agents
- Dianette (co-cyprindiol) is sometimes used as it has anti-androgen properties. However, it has an increased risk of venous thromboembolism compared to other COCPs, therefore it should generally be used second-line, only be given for 3 months and women should be appropriately counselled about the risks
Any role for dietary modification in pts with acne?
No
Erythema nodosum mushkies?
- Inflammation of subcutaneous fat
- Tender, erythematous, nodular lesions
- Occur over shins, may also occur elsewhere e.g. forearms, thighs
- Usually resolves within 6 weeks
- Lesions heal without scarrgin
Erythema nodosum causes?
- Infection = Strep, TB, Brucella
- Inflammation = Sarcoid, IBD, Behcets
- Malignancy/lymphoma
- Drugs = penicillins, sulphonamides, COCP
- Pregnancy
Acanthosis nigricans definition?
Symmetrical, brown, velvety plaques that are often found on the neck, axilla and groin.
Acanthosis nigricans causes?
- T2DM, Obesity, PCOS, Acromegaly, Cushings, Hypothyroidism
- GI Cancer
- Familial
- Prader-Willi syndrome
- Drugs = COCP, Nicotinic acid
Acanthosis nigricans pathophysiology?
Insulin resistance → hyperinsulinemia → stimulation of keratinocytes and dermal fibroblast proliferation via interaction with insulin-like growth factor receptor-1 (IGFR1)
Erythema multiforme mushkies?
A hypersensitivity reaction that is most commonly triggered by infections. It may be divided into minor and major forms.
Previously it was thought that Stevens-Johnson syndrome (SJS) was a severe form of erythema multiforme. They are now however considered as separate entities.
Erythema multiforme features?
- Target lesions initially seen on back of hands/feet before spreading to the torso
- Upper limbs are more commonly affected than the lower limbs
- Pruritis occasionally seen and is usually mild
Erythema multiforme causes?
- Viral = HSV (most common), Orf
- Bacteria = Mycoplasma, Streptococcus
- CTD = SLE
- Sarcoidosis
- Malignancy
- Idiopathic
- Drugs = Penicillins, sulphonamides, carbamazepine, allopurinol, NSAIDs, COCP, Nevirapine
Most common cause of erythema multiforme?
HSV
Erythema multiforme major?
Mucosal involvement
Alopecia classification?
- Scarring = destruction of hair follicle
- Non-scarring = preservation of hair follicle
Scarring alopecia causes?
- Trauma, burns
- Radiotherapy
- Lichen planus
- Discoid lupus
- Tinea capitis
Non-scarring alopecia causes?
- Male-pattern baldness
- Iron and zinc deficiency
- AI = alopecia areata
- Telogen effluvium = hair loss following stressful period
- Trichotillomania
- Drugs = cytoxic drugs, carbimazole, heparin, COCP, colchicine
When can scarring develop in untreated tinea capitis?
If a kerion develops
Lichen sclerosus definition?
An inflammatory condition that usually affects the genitalia and is more common in elderly females. Lichen sclerosus leads to atrophy of the epidermis with white plaques forming
Lichen sclerosus features?
- White patches that may scar
- Itch is prominent
- May result in pain during intercourse or urination
Lichen sclerosus Dx?
Clinical, but biopsy may be performed if atypical features present
Lichen sclerosus Rx?
Topical steroids and emollients
Why does lichen sclerosus require f/up?
Increased risk of vulval cancer
Fitzpatrick skin types?
- Never tans, always burns (often red hair, freckles, and blue eyes)
- Usually tans, always burns
- Always tans, sometimes burns (usually dark hair and brown eyes)
- Always tans, rarely burns (olive skin)
- Sunburn and tanning after extreme UV exposure (brown skin, e.g. Indian)
- Black skin (e.g. Afro-Caribbean), never tans, never burns
Psoriasis exacerbating features?
- Trauma
- Alcohol
- Withdrawal of systemic steroids
- Drugs
Drugs that exacerbate psoriasis?
- BB
- Lithium
- Antimalarials = chloroquine and HCQ
- NSAID
- ACEi
- Infliximab
Why is minocycline avoided in acne now?
Increased risk of drug-induced lupus and hyperpigmentation
Granuloma annulare association?
Diabetes
Granuloma nnulare mushkies?
- Papular lesions that are often slightly hyperpigmented and depressed centrally
- Typically occur on the dorsal surfaces of the hands and feet, and on the extensor aspects of the arms and legs
Leukoplakia mushkies?
- Premalignant condition which presents as white, hard spots on the mucous membranes of the mouth. It is more common in smokers.
- Diagnosis of exclusion. Candidiasis and lichen planus should be considered, especially if the lesions can be ‘rubbed off’
- Biopsies are usually performed to exclude alternative diagnoses such as squamous cell carcinoma and regular follow-up is required to exclude malignant transformation to squamous cell carcinoma, which occurs in around 1% of patients.
Onychomycosis definition?
Fungal infection of the nails
Onychomycosis causes?
- Dermatophytes - mainly Trichophyton rubrum, accounts for 90% of cases
- Yeasts e.g. Candida
- Non-dermatophyte moulds
Fungal nail infection RFs?
DM and age
Fungal nail infection features?
- Unsightly nails
- Thickened, rough, opaque nails
Fungal nail infection Ddx?
- Psoriasis
- Repeated trauma
- Lichen planus
- Yellow nail syndrome
Fungal nail infection Ix?
- Nail clippings
- Nail scrapings
- False-negative for cultures are around 30%, so repeat samples may need to be sent if the clinical suspicion is high
Fungal nail infection Rx?
- No Rx needed if asymptomatic and pt not bothered by appearance
- Dx should be confirmed by microbiology before starting treatment
- Rx depends on organism
Dermatophyte nail infection Rx?
- Oral terbinafine is currently recommended first-line with oral itraconazole as an alternative
- 6 weeks - 3 months therapy is needed for fingernail infections whilst toenails should be treated for 3 - 6 months
- Treatment is successful in around 50-80% of people
Candida nail infection Rx?
- Mild disease should be treated with topical antifungals (e.g. Amorolfine) whilst more severe infections should be treated with oral itraconazole for a period of 12 weeks
- if topical topical treatment is given treatment should be continued for 6 months for fingernails and 9-12 months for toenails
PUVA complication?
SCC
Seborrheoic dermatitis complications?
Otitis externa and blepharitis
Tinea definition?
Dermatophyte fungal infection
3 main Tinea infections?
- Tinea capitis = scalp
- Tinea corporis = trunk, legs or arms
- Tinea pedis = feet
Tinea capitis (scalp ringworm) mushkies?
- A cause of scarring alopecia mainly seen in children
- If untreated, a raised, pustular, spongy/boggy mass called a kerion may form
- Most common cause is Trichophyton tonsurans in the UK and the USA
- May also be caused by Microsporum canis acquired from cats or dogs
- Diagnosis: lesions due to Microsporum canis green fluorescence under Wood’s lamp*. However the most useful investigation is scalp scrapings
Tinea capitis Rx?
- Oral terbinafine for Trichophyton tonsurans
- Oral griseofulvin for Microsporum
- Topical ketoconazole shampoo should be given for the first two weeks to reduce transmission
Tinea corporis (ringworm) mushkies?
- Causes include Trichophyton rubrum and Trichophyton verrucosum (e.g. From contact with cattle)
- Well-defined annular, erythematous lesions with pustules and papules
- Rx = oral fluconazole
Tinea pedis AKA?
Athlete’s foot
Pregnancy sin disorders?
- Atopic eruption of pregnancy
- Polymoprhic eruption of pregnancy
- Pemphigoid gestationis
Atopic eruption of pregnancy mushkies?
- Commonest in pregnancy
- Eczematous, itchy rash
- No specific Rx needed
Polymorphic eruption of pregnancy mushkies?
- Last trimester
- Lesions appear first in abdominal striae
- Rx depends on severity = emollients, mild potency topical steroids, oral steroids
Pemphigoid gestationis mushkies?
- Pruritic blistering lesions
- Often in peri-umbilical region, later spread to trunk, back, buttocks and arms
- Usually presents in 2nd or 3rd trimester and is rarely seen in the first pregnancy
- Oral corticosteroids are usually required
Keloid scars most common where?
Sternum
Keloid scar definition?
Tumour-like lesions that arise from the connective tissue of a scar and extend beyond the dimensions of the original wound
Keloid scar predisposing factors?
- Ethnicity = dark skin
- Young adults, rarely in elderly
- Common sites = sternum, shoulder, neck, face, extensor surface of limbs, trunk
Keloid scars less likely if made where?
Along relaxed skin tension lines
Keloid scar Rx?
- Early keloids may be treated with intra-lesional steroids e.g. triamcinolone
- Excision is sometimes required but careful consideration needs to given to the potential to create further keloid scarring
Angular cheilosis in anorexia cause?
Zinc deficiency (also Vitamin B2 riboflavin deficiency)
Zinc deficiency features?
- Acrodermatitis = red, crusted lesions = acral distribution, peri-orificial, peri-anal
- Alopecia
- Short stature
- Hypogonadism
- Hepatosplenomegaly
- Geophagia (ingesting clay/soil)
- Cognitive impairment
Acrodermatitis enteropathica?
A recessively inherited partial defect in intestinal zinc absorption
What % of pts with psoriatic arthropathy have nail changes?
80-90%
Does psoriatic nail changes affect the severity of psoriasis?
No
Psoriasis nail changes?
- Pitting
- Onycholysis (separation of the nail from the nail bed)
- Subungual hyperkeratosis
- Loss of the nail
Most important factor in determining malignant melanoma prognosis?
Breslow thickness
Breslow thickness and survival rates?
- <0.75 mm = 95-100%
- 0.76 - 1.5 mm = 80-96%
- 1.51 - 4mm = 60-75%
- > 4mm = 50%
Volcano?
Keratoacanthoma
Keratoacanthoma definition?
A benign epithelial tumour. They are more common with advancing age and rare in young people.
Keratoacanthoma features?
- Said to look like a volcano or crater
- Initially a smooth dome-shaped crater
- Rapidly grows to become a crater centrally-filled with keratin
Keratoacanthoma Prognosis and Rx?
Spontaneous regression of keratoacanthoma within 3 months is common, often resulting in a scar. Such lesions should however be urgently excised as it is difficult clinically to exclude squamous cell carcinoma. Removal also may prevent scarring.
Spider naevi definition?
Describe a central red papule with surrounding capillaries. The lesions blanch upon pressure. Spider naevi are almost always found on the upper part of the body.
How to differentiate spider naevi from telangiectasia?
Spider naevi fill from the centre, telangiectasia from the edge
What % of people will have one or more spider naevi?
10-15%, and they are more common in childhood
SPider naevi association?
- Liver disease
- Pregnancy
- COCP
Chronic plaque is what % of psoriasis?
80%
Lichen planus Ps?
Planus:
1. Purple
2. Polygonal
3. Pruritic
4. Papular
Hyperhidrosis Rx?
- 1st line = topical aluminium chloride preparations, main s/e = skin irritation
- Iontophoresis = particularly useful for patients with palmar, plantar and axillary hyperhidrosis
- Botulinum toxin = axillary symptoms
- Surgery = Endoscopic transthoracic sympathectomy. Patients should be made aware of the risk of compensatory sweating
Rodent ulcer?
BCC
BSS and metastases?
Rare
Most common type of cancer in western world?
BCC
BCC features?
- Sun-exposed sites
- Pearly, flesh coloured papule with telangiectasia
- May ulcerate, leaving a central crater
BCC referral?
If suspected, routine referral should be made
BCC Rx?
- Surgical removal
- Curettage
- Cryotherapy
- Topical cream = Imiquimod, Fluorouracil
- Radiotherapy
Pyoderma gangrenosum pathophysiology?
Classified as a neutrophilic dermatosis. Neutrophilic dermatoses are skin conditions characterised by dense infiltration of neutrophils in the affected tissue and this is often seen on biopsy
Pyoderma gangrenosum causes?
- Idipathic in 50%
- IBD
- Rheum = RhA, SLE
- Haem = myeloproliferative disorders, lymphoma, myeloid leukaemias, monoclonal gammopathy (IgA)
- GPA
- PBC
Pyoderma gangrenosum features?
- Location = typically lower limb, often at the site of a minor injury
- Usually starts suddenly, small pustule, red bump or blood-blister
- Skin breaks down, resulting in an ulcer. Edge of ulcer often purple, violaceous and undermined. Ulcer itself may be deep and necrotic
- May be accompanied by fever and myalgia
Pyoderma gangrenosum Dx?
- Often made by the characteristic appearance, associations with other diseases, the presence of pathergy, histology results and when other diseases have been ruled out
- Histology is not specific and can vary depending on the time and site of the specimen but may be helpful in ruling out other causes of an ulcer
Pyoderma gangrenosum Rx?
- Oral steroids 1st line (potential for rapid progression is high)
- Ciclosporin and infliximab in difficult cases
- Surgery should be postponed until the disease process is controlled on immunosuppression to risk worsening of the disease (pathergy)
Shin lesion DDx?
- Erythema nodosum
- Pretibial myxoedema
- Pyoderma gangrenosum
- Necrobiosis lipoidica diabeticorum
Pretibial myxoedema mushkies?
- Symmetrical, erythematous lesions seen in Graves’ disease
- Shiny, orange peel skin
Necrobiosis lipoidica diabeticorum mushkies?
- Shiny, painless areas of yellow/red skin typically on the shin of diabetics
- Often associated with telangiectasia
Topical steroid classification?
- Mild
- Moderate
- Potent
- Very potent
Mild topical steroid?
Hydrocortisone 0.5-2.5%
Moderate topical steroid?
- Betamethasone valerate 0.025% (Betnovate RD)
- Clobetasone butyrate 0.05% (Eumovate)
Potent topical steroid?
- Fluticasone propionate 0.05% (Cutivate)
- Betamethasone valerate 0.1% (Betnovate)
Very potent topical steroid?
Clobetasol propionate 0.05% (Dermovate)
Finger tip rule?
1 finger tip unit (FTU) = 0.5 g, sufficient to treat a skin area about twice that of the flat of an adult hand
Grave’s disease, orange peel shin lesions?
Pretibial myxoedema
HHT definition?
An autosomal dominant condition characterised by multiple telangiectasia over the skin and mucous membranes. Twenty percent of cases occur spontaneously without prior family history.
HHT Diagnostic criteria?
2 = possible Dx, 3 = definite diagnosis
1. Epistaxis
2. Telangiectasias
3. Visceral lesions
4. FHx
HHT visceral lesions?
- GI
- Lung AVM
- Hepatic AVM
- Cerebral AVM
- Spinal AVM
Dermatofibroma AKA?
Histiocytoma
Dermatofibroma definition?
Common benign fibrous skin lesions. They are caused by the abnormal growth of dermal dendritic histiocyte cells, often following a precipitating injury. Common areas include the arms and legs.
Dermatofibroma features?
- Solitary firm papule or nodule, typically on a limb
- Typically 5-10mm in size
- Overlying skin dimples on pinching lesions
Dimple sign?
Dermatofibroma
Impetigo definition?
Impetigo is a superficial bacterial skin infection usually caused by either Staphylcoccus aureus or Streptococcus pyogenes. It can be a primary infection or a complication of an existing skin condition such as eczema, scabies or insect bites. Impetigo is common in children, particularly during warm weather.
The infection can develop anywhere on the body but lesions tend to occur on the face, flexures and limbs not covered by clothing.
Impetigo spread?
Spread is by direct contact with discharges from the scabs of an infected person. The bacteria invade the skin through minor abrasions and then spread to other sites by scratching. Infection is spread mainly by the hands, but indirect spread via toys, clothing, equipment and the environment may occur. The incubation period is between 4 to 10 days.
Impetigo features?
- ‘Golden’ crusted skin lesions typically found around the mouth
- Very contagious
Impetigo Rx?
- Hydrogen peroxide 1% cream for ‘people who are not systemically unwell or at a high risk of complications’
- Topical Abx cream = Fusidic Acid, Mupirocin if fusidic acid resistance suspected
Impetigo extensie disease Rx?
- Oral flucloxacillin
- Oral erythromycin if pen-allergic
Impetigo school exclusion?
Children should be excluded from school until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment
Ruddy complexion?
Polycythaemia
Polycythaemia features?
- Pruritis after warm bath
- ruddy complexion
3 Gout - Peptic ulcer disease
Pityriasis versicolor definition?
Superficial cutaneous fungal infection caused by Malassezia furfur (formerly termed Pityrosporum ovale)
Pityriasis versicolor features?
- Most commonly affects trunk, patches may be hypopigmented/pink/brown. Msay be more noticeable following a suntan
- Scale is common
- Mild pruritis
Predisposing factors?
- Occurs in healthy individuals
- immunosuppression
- Malnutrition
- Cushing’s
Pityriasis versicolor Rx?
- Ketoconazole shampoo
- If failure to respond consider other diagnosis e.g. send scrapings + oral itraconazole
Nickel dermatitis Ix?
Skin patch tst
Exclamation mark?
Alopecia areata
Alopecia areata definition?
A presumed autoimmune condition causing localised, well demarcated patches of hair loss. At the edge of the hair loss, there may be small, broken ‘exclamation mark’ hairs
Alopecia areata prognosis?
Hair will regrow in 50% of patients by 1 year, and in 80-90% eventually. Careful explanation is therefore sufficient in many patients.
Alopecia areata Rx?
- Topical/intralesional corticosteroids
- Topical minoxidil
- Phototherapy
- Dithranol
- Contact immunotherapy
- Wigs
Mycosis fungoides definition?
Rare form of T-cell lymphoma that affects the skin
Mycosis fungoides features?
- Itchy, red patches
- Lesions tend to be of different colours in contrast to eczema/psoriasis where there is greater homogenicity
Mycosis fungoides can present like?
Eczema or psoriasis
Mycosis fungoides on biopsy?
Pautrier microabscesses
Pyogenic granuloma definition?
A relatively common benign skin lesion. The name is confusing as they are neither true granulomas nor pyogenic in nature. There are multiple alternative names but perhaps ‘eruptive haemangioma’ is the most useful.
Pyogenic granuloma causes?
- Trauma
- Pregnancy
- More common in women and young adults
Pyogenic granuloma features?
- Most common sites are head/neck, upper trunk and hands. Lesions in the oral mucosa are common in pregnancy
- Initially small red/brown spot, rapidly progress within days to weeks forming raised, red/brown lesions which are often spherical in shape
- Lesions may bleed profusely or ulcerate
Pyogenic granuloma Rx?
- Lesions associated with pregnancy often resolve spontaneously post-partum
- Other lesions usually persist - removal methods include curettage and cauterisation, cryotherapy, excision
Ataxia telangiectasia AKA?
Louis-Bar syndrome
Actinic keratosis definition?
A common premalignant skin lesion that develops as a consequence of chronic sun exposure
Actinic keratosis features?
- Small, crusty or scaly lesions
- May be pink, red, brown or the same colour as the skin
- Typically on sun exposed areas
- Multiple lesions may be present
Actinic keratoses Rx?
- Prevention of further risk e.g. sun avoidance, sun cream
- Fluorouracil cream = typically a 2 to 3 week course. The skin will become red and inflamed - sometimes topical hydrocortisone is given following fluorouracil to help settle the inflammation
- Topical diclofenac = may be used for mild AKs. Moderate efficacy but much fewer side-effects
- Topical imiquimod
- Cryotherapy, curettage and cautery
Mucosal blisters?
Pemphigus vulgaris
Pemphigus vulgaris definition?
An autoimmune disease caused by antibodies directed against desmoglein 3, a cadherin-type epithelial cell adhesion molecule. It is more common in the Ashkenazi Jewish population.
Pemphigus vulgaris features?
- Mucosal ulceration is common and often the presenting symptom. Oral involvement is seen in 50-70% of patients
- Skin blistering - flaccid, easily ruptured vesicles and bullae. Lesions are typically painful but not itchy. These may develop months after the initial mucosal symptoms. Nikolsky’s describes the spread of bullae following application of horizontal, tangential pressure to the skin
- Acantholysis on biopsy
Pemphigus vulgaris Rx?
- Steroids 1st line
- Immunosuppressants
Is MRSA susceptible to fusidic acid?
No, topical mupirocin should be used instead
Sedating antihistamine?
Chlorphenamine
Non-sedating antihistamine?
Loratadine, cetirizine
What % of pts have a long term remission or cure following oral isotretinoin?
2/3
Retinoids s/e?
- Teratogenicity = 2 forms of contraception
- Dry skin, eyes and lips/mouth = most common
- Low mood
- Raised trigylcerides, hair thinning, nose bleeds
- Intracranial hypertension
- Photosesitivity
Is pruritis a feature of rosacea?
No
DM skin disorders?
- Necrobiosis lipoidica
- Infection = candida, staph
- Neuropathic ulcers
- Vilitigo
- Lipoatrophy
- Granuloma annulare
Psoriasis pathophysiology?
- Multifactorial and not yet fully understood
- Genetic = associated HLA-B13, -B17, and -Cw6. Strong concordance (70%) in identical twins
- Immunological = abnormal T cell activity stimulates keratinocyte proliferation
- Environmental = recognised that psoriasis may be worsened (e.g. Skin trauma, stress), triggered (e.g. Streptococcal infection) or improved (e.g. Sunlight) by environmental factors
Subtypes of psoriasis?
- Plaque = most common sub-type resulting in the typical well-demarcated red, scaly patches affecting the extensor surfaces, sacrum and scalp
- Flexural = skin is smooth
- Guttate = transient psoriatic rash frequently triggered by a streptococcal infection
- Pustular = commonly on palms and soles
Psoriasis other features?
Nail signs and arthritis
Psoriasis complications?
- Psoriatic arthropathy (around 19%)
- Psychological distress
- Increased incidence of CVD, VTE, metabolic syndrome
SCC risk factors?
- Sunlight/PUVA
- Actinic keratoses and Bowne’s disease
- Immunosuppression
- Smoking
- Long standing ulcer e.g. MArjolin’s
- Genetic = xeroderma pigmentosum, oculocutaneous albinism
SCC features?
- Sun exposed sites
- Rapidly expanding painless, ulcerating nodules
- Cauliflower-like appearance
- Areas of bleeding
SCC Rx?
Surgical excision with 4mm margins if lesion <20mm in diameter. If tumour >20mm then margins should be 6mm. Mohs micrographic surgery may be used in high-risk patients and in cosmetically important sites.
SCC poor prognosis?
- Poorly differentiated
- > 20mm deep
- > 4mm deep
- Immunsupression
CC good prognosis?
- Well differentiated
- <20mm deep
- <2mm deep
- No associated diseases
Basal cell carcinoma in high risk area e.g. eyelid, nasal ala Rx?
Refer urgently 2ww
Stevens-Johnson syndrome definition?
A severe systemic reaction affecting the skin and mucosa that is almost always caused by a drug reaction.
Previously it was thought that Stevens-Johnson syndrome (SJS) was a severe form of erythema multiforme. They are now however considered as separate entities.
SJS causes?
- Penicillin
- Sulphonamides
- Lamotrigine, carbamazepine, phenytoin
- Allopurinol
- NSAIDs
- COCP
SJS features?
- Maculopapular rash with target lesions being characteristic = vesicles or bullae, Nikolsky sign positive in erythematous areas
- Mucosal involvement
- Systemic symptoms = fever, arthralgia
SJS Rx?
Hospital admission for supportive treatment
Anti-epileptic and rash?
SJS
SJS Body % affected?
<10%
TEN Body % affected?
> 30%
Erythroderma % affected?
> 90%
Skin disorders affecting soles of the feet?
- Verrucas
- Tinea pedis
- Corn and calluses
- Keratoderma
- Pitted keratolysis
- Palmoplantar pustulosis
- Juvenile plantar dermatosis
Verrucas mushkies?
- Secondary to HPV
- Firm, hyperkeratotic lesions
- Pinpoint petechiae centrally within the lesions
- May coalesce with surrounding warts to form mosaic warts
Corn?
A corn is small areas of very thick skin secondary to a reactive hyperkeratosis
Callus?
A callus is larger, broader and has a less well defined edge than a corn
Keratoderma mushkies?
- Acquired or congenital
- Describes a thickening of the skin of the palms and soles
- Acquired causes include reactive arthritis (keratoderma blennorrhagica)
Pitted keratolysis?
- Affects people who sweat excessively
- Patients may complain of damp and excessively smelly feet
- Usually caused by Corynebacterium
- Heel and forefoot may become white with clusters of punched-out pits
Palmoplantar pustulosis?
- Crops of sterile pustules affecting the palms and soles
- The skin is thickened, red. Scaly and may crack
- More common in smokers
Juvenile plantar dermatosis?
- Affects children. More common in atopic patients with a history of eczema
- Soles become shiny and hard. Cracks may develop causing pain
- Worse during the summer
Acanthosis nigricans associated malignancy?
Gastric cancer
Acquired ichthyosis associated malignancy?
Lymphoma
Acquired hypertrichosis lanuginosa associated malignancy?
GI and lung
Dermatomyositis associated malignancy?
Ovarian and lung
Erythema gyratum repens associated malignancy?
Lung
Erythroderma associated malignancy?
Lymphoma
Migratory thrombophlebitis associated malignancy?
Pancreatic
Necrolytic migratory erythema associated malignancy?
Glucagonoma
Pyoderma gangrenosum associated malignancy?
Myeloproliferative disorders
Sweet’s syndrome associated malignancy?
Haem
Tylosis associated malignancy?
Oesophageal cancer
Port wine stain mushkies?
Vascular birthmarks that tend to be unilateral. They are deep red or purple in colour. Unlike other vascular birthmarks such as salmon patches and strawberry haemangiomas, they do not spontaneously resolve, and in fact often darken and become raised over time. Treatment is with cosmetic camouflage or laser therapy (multiple sessions are required)
Sebaceous cyst definition?
Sebaceous cysts is a general term which encompasses both epidermoid and pilar cysts. It is a bit of a misnomer and probably best avoided where possible.
Epidermoid cysts are due to a proliferation of epidermal cells within the dermis. Pilar cysts (also known as trichilemmal cysts or wen) derive from the outer root sheath of the hair follicle.
Sebaceous cyst typcally contain a?
Punctum
How to prevent sebaceous cyst recurrence?
Surgical excision of the whole structure
Pompholyx definition?
Pompholyx is a type of eczema which affects both the hands (cheiropompholyx) and the feet (pedopompholyx). It is also known as dyshidrotic eczema.
Pompholyx eczema may be precipitated by humidity (e.g. sweating) and high temperatures.
Pompholyx features?
- Small blisters on the palms and soles
- Pruritic = often intensely itchy, sometimes burning sensation
- Once blisters burst skin may become dry and crack
Pompholyx Rx?
- Cool compresses
- Emollients
- Topical steroids
Pompholyx eczema precipitants?
Humidity and high temperatures
Cutaneous manifestation of sarcoidosis?
Lupus pernio
Livedo reticularis definition?
A purplish, non-blanching, reticulated rash caused by obstruction of the capillaries resulting in swollen venules
Livedo reticularis causes?
- Idiopathic (most common)
- PAN
- SLE, APS
- Cryoglobulinaemia
- Ehlers-Danlos syndrome, homocystinuria
Urticaria definition?
A local or generalised superficial swelling of the skin. The most common cause of urticaria is allergy although non-allergic causes are seen.
Urticaria features?
- Pale, pink raised skin –> AKA hives, wheals, nettle rash
- Pruritic
Urticaria Rx?
- Non-sedating antihistamines 1st line
- Prednisolone used for severe or resistant episodes
Curling’s ulcer?
Stress ulcer than can occur after severe burns
Superficial burn healing?
Keratinocytes migrate to form a new layer over the burn site
Full thickness burn healing?
Dermal scarring. Usually need keratinocytes from skin grafts to provide optimal coverage.