Common Skin Conditions Flashcards
What is this skin lesion, what are the features?
BCC:
Pearly edges, central ulceration and bleeding
Often face and head = chronic sun exposure
e.g. inner cathus of eye
Locally aggressive but rarely mets
Can present like a red plaque - not responding to steroids
What is the skin lesion, describe the features
SCC:
Raised, indurated
Tender
Crusted lesion
Bleeds easily
Areas of sun exposure
Also associated with HPV, immunosuppression
Worse prognosis if immunosuppressed or morphoeic sub-type/morphology
Less common than BCC but more dangerous (mets)
Rapid growth (weeks - months)
What is the skin lesion, what are the features
Melanoma
Itchy
Increasing in size
Raised
Darkly pigmented
Irregular borders
Crusting and bleeding
What is the skin lesion?
Seborrheic keratosis
- generally benign, pigemented lesion.
- sun-induced
Clinical Features of Atopic Eczema
Itchy ++
Erythematous
Diffuse
Worse with heat and dry
Flexor surfaces – thinnest skin
Risk Factors and Triggers for Eczema
Genetic Predisposition (FHx)
Atopy/Atopic Triad
Asthma
Hay-fever
Eczema
Environmental Triggers
Irritants
Allergy
Heat
Infection
Stress and anxiety
Complications of Eczema
- Bacterial Superinfection (often Staph)
- Eczema herpeticum - secondary HSV infection (medical emergency! Risk of corneal scarring)
- contact dermatitis (determie if allergic or due to irritant)
-
Management of Eczema
- no-pharmacological/behavioural
- pharmacological
General:
- avoid soaps
- regualr emollient to avoid dry skin (+ if itchy increased infection risk)
- warm, not hot showers
Pharm:
- topical steroids (more potent for hands/feet/thicker skin)
- mild steroid for face or NSAI creams
- treat infection w oral ABx
other options
- only use oral pred short term.
- medium-long term - may use steroid sparing agents (azathioprine, methotrexate etc.) but caution of side effects.
- phototherapy with UVB (but CI in previous melanoma)
- wet dressings
Eczema variants
Discoid (can mimic psoriasis)
Pompholyx
Asteatotic (often in elderly, seasonal)
Diffuse erythrodermic (significant morbidity - treat with intense topical and systemic immunosuppresion)
Clinical Features of Psoriasis
Silvery Scaly
Well demarcated plaques
Often symmetrical
Erythematous, salmon pink
Extensor surfaces
Itchy (but not like eczema)
Likes hairy surfaces and folds (nasal cleft, under breast, groin, penis)
Pathogenesis and triggers/exacerbating factors for Psoriasis
Some genetic predisposition
Age of onset – 2 peaks in 20s and 50s
Pathophy: Hyper proliferative skin, chronic inflammatory disease
Genetic + environmental
Exacerbated by
- Trauma
- Infection
- Sunlight (minority of patients)
- Drugs (anti-malarial, beta-blockers, NSAIDs, anti-TNF)
- Rebound flare with corticosteroid withdrawal
- Psychological factors
Treatment of Psoriasis
- topical
- systemic
- other
Topical – steroids, tars, calcipotriol, dithranol, keratolytics, emollients
Phototherapy – narrowband UVB
Systemic (different to eczema as diff component of immune system)
Nioticasone, methotrexate, cyclosporine A, biologic treatments (e.g. TNF alpha inhibitors - Infliximab )
→ often use a combination
Variants and complications of Psoriasis
- Scalp
- Nail psoriasis (pitting, onycholiasis, sub-ungual keratosis)
- Guttate/”raindrop” - may be triggered by strep infection, ~ 1-2 weeks later
- Generalised pustular psoriasis = medical emergency - risk of pre-renal impairment, high output cardiac failure, sepsis.
- Psoriatic arthritis
Pathogenesis and factors in development of Acne
disorder of polisebaceous unit - resulting in bacterial colonisation, w icnreased sebum production + inflammation.
Predisposing factors
- strong genetic link
- often starts in adolescence = increased sebum producion
- hormonal component i.e. menstruation, pre-menstrual flare
- medications - lithium, anabolic steroids
- topical occlusion i.e. makeups etc.
Acne treatment
- dietary modification
- Topical treatment
- salicylic acid (dissolve comedones)
- anti-bacterial - topical benzoyl peroxide, erythromyicin, clindamycin
- combination topical treatments: comedolytic + antibacteriaL
SYSTEMIC
- systemic antibiotics - doxycycline, erythromycin (acne recurs on cessation) [especially pustular acne]
- anti-androgen OCP (female patients only) = reduced sebum secretion (in hormonal acne)
- anti-androgens (female patients only) e.g. spirinolactone, cyproterone acetate (in hormonal acne but will cause menstrual irregularities).
- Systemic Retinoids (Isoretinoin) = comedolytic, reduces sebaceous gland activity BUT side effects
How is a diagnosis of scabies confirmed?
skin scraping of burrow, examination under light microscope (though often treat just on suspicion of scabies)
