DERM - common dermatological conditions Flashcards
Describe atopic eczema
- appearance
- atopic triad
- Px
- Erythematous, ill defined, scaly, patches in flexures
- Triad: asthma + hayfever + eczema
Px: •Itchy ++ •Erythematous •Diffuse •Flexural- thinnest skin •Worse in winter (dry) •Worse in summer (heat)
What are the risk factors for eczema?
Genetic:
- Filaggrin mutation (reduced barrier function)
Environmental: •Irritants (soaps etc) •Allergy •Heat •Infection (Staph.) •“Itch-scratch cycle” •Stress and anxiety
(2) Cx of eczema
- Bacterial Superinfection
- Eczematous skin lacks naturally occuring antibacterial peptides
- Often superinfected with Staphylococcus aureus producing a “golden crust”
- Successful treatment requires systemic anti-staph antibiotics
- Eczema Herpeticum
- Secondary infection by HSV virus
- Sudden onset, worsening of pre-existing eczema with painful vesicles and “punched out” erosions
- Medical emergency, risk of corneal scarring
- Needs assessment by ophthalmologist and systemic antiviral treatment
Rx of atopic eczema
General measures
•Avoid soap ( use soap substitute, non detergent)
•Regular emollient (eg sorbolene cream)
•Warm, not hot showers
Specific measures
•Topical steroid to inflamed areas eg potent steroid to body;
•Mild steroid for face, or non steroid anti inflammatory creams (pimecrolimus)
•Treat infection if suspected with systemic antibiotics
- Wet dressings
- Phototherapy with UVB
- Systemic immunosuppression with oral prednisolone, methotrexate etc
Describe psoriasis
- appearance
- Px
- age of onset
- Risk factor
Appearance: •Well demarcated plaques •Extensor surfaces •Very erythematous/salmon pink •Silvery Scaly +++
Px: •Extensor rash •Symmetrical •Silvery scale •Well demarcated •Can be itchy, but not like eczema
Age of onset: 20s & 50s (bimodal)
Genetic predisposition (30% FMHx)
Describe post-streptococcal guttate psoriasis
- Occurs 1-2 weeks after Streptococcus URTI/tonsillitis
- Sudden generalised onset of small plaque psoriasis
- Most will clear with treatment but recurs if Strep. infection again
- Very responsive to phototherapy
Describe generalised pustular psoarisis
- Acute pustular flare of psoriasis is often accompanied by systemic symptoms of fever and chills.
- Leads to loss of barrier function, thermoregulation, protein loss.
- Risk of pre-renal impairment, high output cardiac failure, sepsis.
- Needs hospital admission to stabilize.
A medical emergency!
Describe psoriatic arthritis
Affects 10% of psoriasis patients
•More common if nail psoriasis •Various types; - Oligoarthritis - Distal symmetrical polyarthritis - Ankylosing Spondylitis - Rheumatoid-like - Arthritis mutilans
Rx of psoriasis
- Topical – steroids, tars, calcipotriol, dithranol, keratolytics, emollients
- Phototherapy – Narrowband UVB treatment, (PUVA)
- Systemic – oral acitretin, methotrexate, cyclosporin A, biologic treatments.
Often used in combination.
Describe acne
- disorder of which unit
- how common in post-pubertal
- Disorder of pilosebaceous unit
- Common- Occurs in approx 80% of post-pubertal individuals
- Moderate to severe in 15-20% of cases
- Teenage disease, but can persist into adulthood
What are the causes of acne?
- Starts in adolescence with increasing sebum production
- Strong genetic component
- Can be flared by hormonal factors (menstruation), picking, emotional stress
- Medications: Lithium, anabolic steroids, topical corticosteroids (steroid acne)
- Topical occlusion – “oily” makeup, moisturisers, headwear and hairstyling
What are the 4 components of acne?
- Abnormal keratinization of sebaceous duct
- Colonization with bacteria
- Propionobactrium acnes - Increase in androgen levels leading to increased sebum production
- Inflammation
Describe hormonal acne
Adult onset acne in female
•Premenstrual flare
•Mainly on lower face
•Treatment: Anti-androgenic OCP +/- anti-androgen
•If associated with other signs of androgenisation – eg hirsutism, androgenetic alopecia, consider polycystic ovarian syndrome (PCOS)
Rx of acne
Topicals:
- keratolytics
- comedolytic
- anti-bacterial treatments
- combination treatments
Systemic:
- Systemic antibiotics
- antiandrogenic OCP (females only)
- antiandrogens (females only)
- Systemic retinoids
Who gets rosacea?
- Affects women more than men (3:1)
- Affects middle aged > young individuals
- Sun-damaged, Celtic skin more affected
- Men can get tissue hyperplasia as a complication- rhinophyma
What are the 2 components to rosacea?
- Vascular reactivity – redness, flushing
- Inflammatory rosacea – papules, pustules
both can occur at the same time or in isolation
What are triggers of vascular reactivity in rosacea?
- Sunlight
- Alcohol
- Hot foods and drinks
- Spicy foods
- Emotion
- Heat
- Topical steroids may worsen rosacea
Long term Cx of rosacea
Vascular dilatation – redness, telangiectasia
Tissue hypertrophy – Rhinophyma
Rx of rosacea
General – Avoid triggers •Sun-avoidance – SPF 30+ sunblocks daily •Avoiding spicy foods, alcohol •Avoid topical steroids •Skin care advice – use mild cleansers and bland, non-perfumed moisturisers •Stress management
Specific treatment
Vascular rosacea
- Vascular laser
Inflammatory rosacea
- Topical metronidazole gel
- Topical azaleic acid
- Systemic antibiotics – eg doxycycline or minocycline
- Systemic isotretinoin
Rhinophyma
- Ablative laser or surgery
Describe clinical Px of scabies
Px:
•Intensely itchy rash, often starting on hands, interdigital spaces and feet
•Itch is worse at night
•Spreads to genital areas, generalised body rash
•Spares face and head in adults
•Other close contacts develop itch after a few weeks (incubation period 4-6 weeks)
Describe appearance of scabies rash
- Scabies burrows – Serpiginous scaly lines, inflammatory scaly papules on hands, feet, interdigital areas, genitals – These are where mites live
- Non-specific eczematous rash – This is a secondary hypersensitivity reaction and occurs later
How do you Dx scabies?
skin scraping of burrow and examination under light microscopy
Can see scabies mite, egg & faeces
Rx of scabies
General aspects:
•Treat all close contacts – sexual contacts and household at the same time
•Index case is usually retreated again after one week
•Post-scabetic itch can take weeks to settle
Topical:
•5% PERMETHRIN cream 1st line treatment for scabies
•Apply cream all over from neck down – esp hands, genitalia and under nails with naibrush (care with handwashing)
•Infants (>6 months) and children need to treat scalp as well
•Leave on overnight (8hrs)
•Wash off in morning, treat clothing with hot wash and tumble dry (>55c)
After scabicide treatment, what should be treated?
Eczema
- Recommend potent topical steroid with emollients with oral antihistamines
- Treat secondary infection if present with antibiotics
What are (4) variants of eczema?
- Discoid eczema. Mimics psoriasis & tinea.
- Asteatotic eczema (front legs of elderly)
- Pompholyx/vesicular hand & foot eczema (avoid detergents/soaps)
- Diffuse erythrodermic eczema (>90% BSA severe eczema, treat like a burn. Significant morbidity).-> intense topicals & systemic immnosuppression
