Week 2 derm Flashcards
cellulitis
what is it?
most common organisms?
4 complications?
risk factors?
presentation?
investigations?
bacterial infection of the skin involving the deep subcutaneous tissue and dermis
Streptococcus pyogenes and Staphylococcus aureus
necrotizing fasciitis, sepsis, persistent leg ulceration, and recurrent cellulitis
Risk factors include skin trauma, ulceration, and obesity.
red spreading along the skin, swollen, fever
diagnosis can be made by examination, history and swabs
impetigo
what is it?
most common organisms?
4 complications?
risk factors?
presentation?
investigations?
common superficial bacterial infection of the skin.
Staphylococcus aureus, Streptococcus pyogenes
glomerulonephritis or cellulitis
vesicles, pustules, exudate with brown crust
history and examination and swabs for culture
advise on skin hygiene , stay from school or work until lesions
non-bullous infection with topical hydrogen peroxide
if severe = fluclox or clarithromycin
athletes foot
what is it?
most common organisms?
risk factors?
presentation?
investigations?
AKA tinea pedis
superficial infection of the skin on the foot caused by dermatophytes
Trichophyton rubrum
hot, humid climates or working environments; occlusive footwear; hyperhidrosis; walking on contaminated surfaces; and immunocompromised states.
itchy, flaky, or painful skin of the feet
history examination and culture
self care topical antifungals (terbinafine), if severe topical corticosteroid, oral terbinafine
urticaria
what is it?
management?
Mast cell releases mediators causing locally increased permeability of capillaries and venules - Involves only epidermis
Antihistamines
Corticosteroids if severe
erythema nodosum
what is it?
causes?
presentation?
management?
Hypersensitivty reaction to a variety of stimuli causing inflammation of fat cells under skin
Strep Pyogenes, TB, Malignancy, IBD, drugs e.g. penicillin
Tender nodules usually on shins , after 2 weeks leave bruise like discolouration as they resolve
50% may experience arthralgia or morning stiffness
Generally self limiting
Cool compresses and bed rest
NSAIDs
Treat underlying cause
eczema
what is it?
presentation?
conservative management?
pharmacological therapy
Usually develops in childhood and resolves during adulthood
Itchy erythematous dry scaly patches normally on flexor aspects (but can be on face and extensor aspects in infants
Excoriation
Lichenification
Nail pitting
Hypo/Hyperpigmentation
Chronic lesions - dry and scaly (erythematous or grey/brown)
Avoid triggers (such as wool/synthetic fibres and extremes of temperature) Frequent emollients
Topical Therapies - topical steroids (for flares) or topical immunomodulators (tacrolimus)
Oral therapies - antihistamines
Immunosupressants for severe non responsive cases
psoriasis- what is it?
State four subtypes of Psoriasis
management ?
Chronic Inflammatory skin disease due to hyper proliferation of keratinocytes and inflammatory cell infiltration - Abnormal keratinocyte differentiation (decreasing keratinocyte transit time)
Chronic Plaque (most common)
Guttate (raindrop lesions, post strep)
Seborrhoeic (scalp and behind ears, blepharitis)
Pustular (plantar, palma
vitiligo
presentation?
associated conditions?
Vitiligo is an autoimmune condition which results in the loss of melanocytes and consequent depigmentation of the skin- develops by the age of 20-30 years old
well circumcised depigmented patches of skin, tends to be on periphery, trauma may create new lesions
- type 1 diabetes mellitus
- Addison’s disease
- autoimmune thyroid disorders
- pernicious anaemia
- alopecia areata
sun block, camouflage makeup, topical corticosteroid, topical tacrolimus
Hereditary Angio-Oedema
Autosomal dominant deficiency of C1 esterase inhibitor (which normally aims to prevent reactivation of compliment system)
Causes recurrent swelling
Treated by C1 Esterase Inhibitor Concentrate (found in FFP)
acne vulgaris
what is it?
topical therapy
oral therapy
occurs in adolescence, obstruction of the pilosebaceous follicle with keratin plugs which results in comedones, inflammation and pustules.
can be inflammatory or non inflammatory
Benzoyl Peroxide - reduces sebum production and growth of P.Acnes (may cause burning sensation)
Topical Abx - Clindamycin/Tetracycline (normally combined with another therapy)
Topical Retinoids - Tretinoin, anti inflammatory (contraindicated in pregnancy)
Lymecycline/Doxycycline (erythro if preg)
Anti-Androgens - COCP
Oral Isotretinoin (VERY TOXIC) - takes 3-4 months to work
steven johnson syndrome
what is it?
treatment?
A severe form of Erythema Multiforme, caused by hypersensitivity reaction normally to drugs such as Allopurinol/Carbemazepine/Penicillins
At least two mucosal sites involved
Remove offending cause
Supportive
Immunomodulation (potentially pulsed steroids to avoid poor wound healing)
Plasmphoresis
eythroderma
what is it?
4 causes?
presentation?
complications?
management?
Exfoliative dermatitis involving atleast 95% skin’s surface
Previous skin disease, Lymphoma, Drugs (Penicillin, Allopurinol), Idiopathic
Skin appears inflamed, oedematous and scaly
Pt feels systemically unwell with malaise and lymphadenopathy
Hypothermia, Secondafry Infection, High Output Heart Failure
Emollients and wet wraps to maintain skin’s moisture
Topical steroids
necrotising Fasciitis
what is it? what is it caused by?
presentation?
management?
Rapidly progressing infection of the deep fascia causing necrosis of subcutaneous tissue - Normally caused by Group A Strep, or a mixture of aerobic and anaerobic
Severe pain, Erythema, Tachycardia, Crepitus (Subcutaneous Emphysema)
Extensive Surgical Debridement
IV Antibiotics
Staphylococcal Scalded Syndrome
scabies
what is it?
presentation?
management?
The scabies mite (Sarcoptes scabiei) burrows into the skin, laying its eggs in the stratum corneum. Itching associated with scabies is due to a delayed-type IV hypersensitivity reaction to mites/eggs which occurs about 30 days after the initial infection.
- 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
- permethrin 5% is first-line
- malathion 0.5% is second-line
- give appropriate guidance on use (see below) - avoid close contact, household members treated, wash clothes !!
- pruritus persists for up to 4-6 weeks post eradication
neuropathic ulcer
what is it?
management?
Often painless, variable in size and shape
Granulating base
Often in pressure sites (heels, soles, toes)
Can be Neuroischaemic
Wound debridement
Regular repositioning
Good nutrition
Appropriate footwear
venous ulcer
what is it?
management?
Large shallow and irregular usually in malleolar area
Exudative and granulating base
Pain on standing
compressive bandage
arterial ulcer
what is it?
management?
Small and sharply defined with a deep necrotic base
Abent peripheral pulses, shiny skin and loss of hair
Pain at night/elevation of leg
Vascular Reconstruction
Rosacea
presentation?
- typically affects nose, cheeks and forehead
- flushing is often first symptom
- telangiectasia are common
- later develops into persistent erythema with papules and pustules
- rhinophyma
- ocular involvement: blepharitis
- sunlight may exacerbate symptoms
topical metronidazole may be used for mild symptoms, sun cream
Eczema herpeticum
what is it?
presentations?
management?
Eczema herpeticum describes a severe primary infection of the skin by herpes simplex virus 1 or 2.
children with atopic eczema and often presents as a rapidly progressing painful rash.
monomorphic punched-out erosions (circular, depressed, ulcerated lesions) usually 1–3 mm in diameter are typically seen.
IV aciclovir
Dermatofibroma
benign fibrous skin lesions - can be caused by injury
- solitary firm papule or nodule, typically on a limb
- typically around 5-10mm in size
- overlying skin dimples on pinching the lesion
Guttate psoriasis
what is it ?
presentation?
treatment?
It may be precipitated by a streptococcal infection 2-4 weeks prior to the lesions appearing.
- tear drop papules on the trunk and limbs
- gutta is Latin for drop
- pink, scaly patches or plques of psoriasis
- tends to be acute onset over days
- most cases resolve spontaneously within 2-3 months
- there is no firm evidence to support the use of antibiotics to eradicate streptococcal infection
- topical agents as per psoriasis
- UVB phototherapy
- tonsillectomy may be necessary with recurrent episodes
Atopic eruption of pregnancy
Polymorphic eruption of pregnancy
Pemphigoid gestationis
- is the commonest skin disorder found in pregnancy
- it typically presents as an eczematous, itchy red rash.
- no specific treatment is needed
- 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
- 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
when is Acanthosis nigricans seen
type 2 diabetes mellitus
gastrointestinal cancer
obesity
polycystic ovarian syndrome
acromegaly
Cushing’s disease
hypothyroidism
familial
Prader-Willi syndrome
drugs = combined oral contraceptive pill
nicotinic acid
insulin resistance → hyperinsulinemia → stimulation of keratinocytes and dermal fibroblast proliferation via interaction with insulin-like growth factor receptor-1 (IGFR1)
Pityriasis versicolor
what is it?
presentation?
risk factors?
treatment?
tinea versicolor, is a superficial cutaneous fungal infection caused by Malassezia furfur
most commonly affects trunk, patches may be hypopigmented, pink or brow, scale, pruritus
immunosupression, malnutrition, cushings
- topical antifungal. NICE Clinical Knowledge Summaries advise ketoconazole shampoo as this is more cost effective for large areas
- if failure to respond to topical treatment then consider alternative diagnoses (e.g. send scrapings to confirm the diagnosis) + oral itraconazole
keloid scar
what is it?
risk factors?
tumour-like lesions that arise from the connective tissue of a scar and extend beyond the dimensions of the original wound
- ethnicity: more common in people with dark skin
- occur more commonly in young adults, rare in the elderly
- common sites (in order of decreasing frequency): sternum, shoulder, neck, face, extensor surface of limbs, trunk
intralesional steroids on early keloid
excision of scar may be needed
malignant melaoma
3 prognostic factors?
3 risk factors?
breslow thickness, ulceration, mitoses
UV exposure
Type 1 Skin
Dysplastic Naevus Syndrome
basal cell carcinoma
what is it?
presentation?
slow-growth and local invasion. Metastases are extremely rare. most common type is nodular BCC
- sun-exposed sites, especially the head and neck account for the majority of lesions
- initially a pearly, flesh-coloured papule with telangiectasia
- may later ulcerate leaving a central ‘crater’
squamous cell carcinoma
risk factors?
treatment?
common variant of skin cancer. Metastases are rare but may occur in 2-5% of patients.
- immunosuppression e.g. following renal transplant, HIV
- smoking
- long-standing leg ulcers (Marjolin’s ulcer)
- genetic conditions e.g. xeroderma pigmentosum, oculocutaneous albinism
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.
management of cellulitis, eron scale?
Eron classification of cellulitis is a guide for making management decisions:
Class I — there are no signs of systemic toxicity or uncontrolled comorbidities.
Class II — the person is either systemically unwell or systemically well but with a comorbidity
Class III — the person has significant systemic upset (such as acute confusion, tachycardia, hypotension), or unstable comorbidities
Class IV — the person has sepsis or a severe life-threatening infection, such as necrotizing fasciitis.
flucloxacillin, clarithromycin or erythromyicn (pregnant)
angio oedema
3 main causes?
welling of deep dermis, subcutaneous, or submucosal tissue, often affecting the face (lips, tongue, and eyelids), genitalia, hands, or feet.
allergic , non-allergic drug reaction (usually caused by angiotensin-converting enzyme [ACE] inhibitor treatment), hereditary angio-oedema , acquired angio-oedema), and idiopathic angio-oedema.
treat with non sedating anti histamines and oral cortico steroids
erythema multifome
what is it?
presentation?
management?
skin reaction that can be triggered by an infection or some medicines
Rash begins on extremities, symmetrically
Initially a dull red macule that develops a central papule/bullae to form a target lesion
Self Limiting
Analgesics and Steroid Creams
What is SCORTEN
Predicts mortality for Steven Johnson Syndrome
Score greater than 3 requires ITU
Differentiating guttate psoriasis and pityriasis rosea
how does psoriasis present?
complications?
Well demarcated erythematous scaly plaques, common on extensor surfaces and scalp Nail changes (pitting,oncholysis) and Psoriatic Arthropathy
- psoriatic arthropathy (around 10%)
- increased incidence of metabolic syndrome
- increased incidence of cardiovascular disease
- increased incidence of venous thromboembolism
- psychological distress
psoriasis treatment?
Topical - Vitamin D Analogues (Calcipitriol), Topical Steroids
Oral - Methotrexate, Retnoids
Phototherapy
narrowband ultraviolet B light is now the treatment of choice. If possible this should be given 3 times a week
photochemotherapy is also used - psoralen + ultraviolet A light (PUVA)
adverse effects: skin ageing, squamous cell cancer (not melanoma)
State three secondary viral infectons of Eczema
Molluscum Contagiosum
Viral Warts
Eczema Herpeticum
