derm Flashcards
Acanthosis nigricans ass/w
Gastric cancer
Acquired ichthyosis ass/w
Lymphoma
Acquired hypertrichosis lanuginosa
Gastrointestinal and lung cancer
Polymorphic eruption of pregnancy
- Pruritic condition associated with last trimester
- Lesions often first appear in abdominal striae
- Management depends on severity: emollients, mild potency topical steroids and oral steroids
may be used
Pemphigoid gestationis
- Pruritic blistering lesions
- Often develop in peri-umbilical region, later spreading to the trunk, back, buttocks and arms
- Usually presents 2nd or 3rd trimester and is rarely seen in the first pregnancy
- Oral corticosteroids are usually required
Skin disorders associated with TB
- Lupus vulgaris (accounts for 50% of cases) * Erythema nodosum
- Scarring alopecia
Scrofuloderma: breakdown of skin overlying a tuberculous focus - Verrucosa cutis * Gumma
most common form of cutaneous TB seen in the Indian subcontinent
Lupus vulgaris
. The initial lesion is an erythematous flat plaque which gradually becomes elevated and may ulcerate later
Hypothyroidism skin
- Dry (anhydrosis), cold, yellowish skin
- Non-pitting oedema (e.g. hands, face)
- Dry, coarse scalp hair, loss of lateral
aspect of eyebrows - Eczema
- Xanthomata
Hyperthyroidism skin
Pretibial myxoedema: erythematous, oedematous lesions above the lateral malleoli
* Thyroid acropachy: clubbing
* Scalp hair thinning
* ↑ sweating
Erythema multiforme:
Target lesions (typically worse on peripheries e.g. Palms and soles)
* Severe = stevens-johnson syndrome (blistering and mucosal involvement)
Causes
* Idiopathic
* Bacteria: mycoplasma, Streptococcus
* Viruses: herpes simplex virus, Orf
* Drugs: penicillin, sulphonamides,
carbamazepine, allopurinol, NSAIDs,
oral contraceptive pill, nevirapine
* Connective tissue disease e.g.
Systemic lupus erythematosus
* Sarcoidosis
* Malignancy
Scarring alopecia
- Trauma, burns
- Radiotherapy
- Lichen planus
- Discoid lupus
- Tinea capitis*
- TB
Non-scarring alopecia
- ♂-pattern baldness
- Drugs: cytotoxic drugs, carbimazole,
heparin, oral contraceptive pill,
colchicine - Nutritional: iron and zinc deficiency
- Autoimmune: alopecia areata
- Telogen effluvium (hair loss following stressful period e.g. Surgery)
- Trichotillomania “hair loss from a patient’s repetitive self-pulling of hair”
Alopecia areata
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 treatment
Hair will regrow in 50% of patients by 1 year, and in 80-90% eventually. Careful explanation is therefore sufficient in many patients. Other treatment options include:
* Topical or intralesional corticosteroids
* Topical minoxidil
* Phototherapy
* Dithranol
* Contact immunotherapy * Wigs
Shin lesions:
The differential diagnosis of shin lesions includes the following conditions:
* Erythema nodosum
* Pretibial myxedema
* Pyoderma gangrenosum
* Necrobiosis lipoidica diabeticorum
Erythema nodosum
Erythema nodosum
* Symmetrical, erythematous, tender, nodules which heal without scarring
* Most common causes are streptococcal infections, sarcoidosis, inflammatory bowel disease and
drugs (penicillins, sulphonamides, oral contraceptive pill)
Pretibial myxedema
Pretibial myxedema
* symmetrical, erythematous lesions seen in Graves’ disease
* shiny, orange peel skin
pyoderma gangrenosum
yoderma gangrenosum
* Initially small red papule
* Later deep, red, necrotic ulcers with a violaceous border
* Idiopathic in 50%, may also be seen in inflammatory bowel disease, connective tissue disorders
and myeloproliferative disorders
Necrobiosis lipoidica diabeticorum
Shiny, painless areas of yellow/red skin typically on the shin of diabetics
* Often associated with telangiectasia
Erythema nodosum overview
Inflammation of subcutaneous fat
* Typically causes tender, erythematous,
nodular lesions
* Usually occurs over shins, may also occur
elsewhere (e.g. Forearms, thighs)
* Usually resolves within 6 weeks
* Lesions heal without scarrin
Erythema nodosum causes
Causes
* Infection: streptococci, TB, brucellosis
* Systemic disease: sarcoidosis, inflammatory
bowel disease, Behcet’s
* Malignancy/lymphoma
* Drugs: penicillins, sulphonamides,
combined oral contraceptive pill
* Pregnancy
Pyoderma Gangrenosum futures
Typically on the lower limbs
* Initially small red papule
* Later deep, red, necrotic ulcers with a violaceous border
* May be accompanied systemic systems e.g. Fever, myalgia
Pyoderma Gangrenosum causes
- Idiopathic in 50%
- IBD: ulcerative colitis, crohn’s
- Rheumatoid arthritis, SLE
- Myeloproliferative disorders
- Lymphoma, myeloid leukemias
- Monoclonal gammopathy (IgA)
- Primary biliary cirrhosis
Pyoderma Gangrenosum causes
Management
* The potential for rapid progression is high in most patients and whilst topical and intralesional steroids have a role in management most doctors advocate oral steroids as first-line treatment
* Other immunosuppressive therapy, for example Cyclosporin and infliximab, have a role in
difficult cases
Seborrhoeic dermatitis causes
inflammatory reaction related to a proliferation of a normal skin inhabitant, a fungus called Malassezia (formerly known as Pityrosporum ovale).
Seborrhoeic dermatitis features
Features
* Eczematous lesions on the sebum-rich areas: scalp (may cause dandruff), periorbital, auricular and nasolabial folds
* Otitis externa and blepharitis may develop
Seborrhoeic dermatitis management
Scalp disease management
* Over the counter preparations containing zinc pyrithione (‘Head & Shoulders’) and tar (‘Neutrogena T/Gel’) are first-line
* The preferred second-line agent is ketoconazole
* Selenium sulphide and topical corticosteroid may also be useful
Face and body management
* Topical antifungals: e.g. Ketoconazole
* Topical steroids: best used for short periods
* Difficult to treat - recurrences are common
Malignant Melanoma: prognostic factor
invasion depth of a tumour (Breslow depth) is the single most important factor in determining prognosis of patients with malignant melanoma
Impetigo treatment
topical fusidic acid → oral flucloxacillin / topical mupirocin
Erythema ab igne
kin disorder caused by over exposure to infrared radiation. Characteristic features include erythematous patches with hyperpigmentation and telangiectasia. A typical history would be an elderly women who always sits next to an open fire (ovens)
If the cause is not treated then patients may go on to develop squamous cell skin cancer
Actinic keratoses features
premalignant skin lesion
- Small, crusty or scaly, lesions
- May be pink, red, brown or the same color as the skin
- Typically on sun-exposed areas e.g. Temples of head
- Multiple lesions may be present
Actinic keratoses Management options include
- 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: trials have shown good efficacy
- Cryotherapy
- Curettage and cauter
Skin & DM: Necrobiosis lipoidica
o Shiny, painless areas of yellow/red/brown skin typically on the shin o Often associated with surrounding telangiectasia
Skin & DM: Infection
o Candidiasis
o Staphylococcal
Skin & DM
Neuropathic ulcers
* Vitiligo
* Lipoatrophy
* Granuloma annulare
LICHEN
* Planus:
Purple, Pruritic, Papular, Polygonal rash on flexor surfaces. Wickham’s striae over
surface. Oral involvement common
LICHEN Sclerosus
itchy white spots typically seen on the vulva of elderly women
Lichen Planus causes
Is a skin disorder of unknown etiology; most probably being immune mediated
Features
* Itchy, papular rash most common on the
palms, soles, genitalia and flexor surfaces
of arms
* Rash often polygonal in shape, ‘white-lace’
pattern on the surface (wickham’s striae)
* Koebner phenomenon seen
* Mucous membrane involvement
* Nails: thinning of nail plate, longitudinal
ridging
Lichenoid drug eruptions - causes: * Gold
* Quinine * Thiazides
LICHEN Sclerosus
Was previously termed lichen sclerosus et atrophicus. It is an inflammatory condition which usually affects the genitalia and is more common in elderly ♀s. Lichen sclerosus leads to atrophy of the epidermis with white plaques forming
Features
* Itch is prominent
A biopsy is often performed to exclude other diagnoses
Management
* Topical steroids and emollients
* ↑ risk of vulval cancer
Scabies features
Features
* Widespread pruritus
* 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 causes
mite Sarcoptes scabiei and is spread by prolonged skin contact. It typically affects children and young adults.
Scabies management
Management
* Permethrin 5% is first-line
* Malathion 0.5% is second-line
* Give appropriate guidance on use (see below)
* Pruritus persists for up to 4-6 weeks post eradication