Dermatology: Clinical Cases of Rash Flashcards
Examination of general skin in psoriasis reveals?
Plaques on extensor surfaces, usually, e.g: extensor elbows, knees and shins
Examination of scalp in psoriasis reveals?
Local adherent scale and erythema at the hairline
Nail signs in psoriasis?
Nail dystrophy:
Pitting
Onycholysis - lifting up of nail plate that may discolour the nail
Subungual hyperkeratosis (thickening)
Longitudinal ridging
Joint disease in psoriasis?
Psoriatic arthritis (joint swelling), e.g: tender hands
Cause of psoriasis?
Multi-factorial disease with:
Genetic factors
Environmental factors inc. stress, drugs and infections
What is the most common type of psoriasis and how does it present?
Chronic plaque psoriasis (psoriasis vulgaris) presents as:
Symmetrical, sharply dermarcated, scaly and erythematous plaques
Common sites affected are the extensors, scalp, sacrum, hands, feet, trunk and nails
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What is the Koebner phenomenon?
Psoriasis develops in areas of skin trauma, e.g: a scratch mark or scar
What is Auspitz sign?
Removal of surface scale reveals tiny bleeding points (dilated capillaries in elongated dermal papillae, which have come close to the surface)
What is guttate psoriasis?
Multiple small scaly plaques that tend to affect most of the body, unlike psoriasis vulgaris (where extensors are mostly affected)
Lesions are conc. around the trunk, upper arms and thighs
What is palmoplantar pustular psoriasis?
Chronic pustular condition affecting the palms and soles; characterised by thickened, scaly, erythematous skin that easily develops fissures
What is erythrodermis (or widespread pustular) psoriasis?
Rare and is a generalised redness of the skin that can be fatal; it may be precipitated by, e.g: infections, alcohol, low Ca2+
Co-morbidities of psoriasis?
Psoriatic arthritis, metabolic syndrome (obesity, hypertension, diabetes, dyslipidaemia), Crohn’s disease, cancer, depression, uveitis
Why is life expectancy reduced by 4 years, in patients with severe psoriasis?
Increased CV risk (3x for MI)
Topical therapies available for psoriasis?
Vitamin D analogues, e.g: calcitriol and calcipotriol
Coal tar
Dithranol
Steroid ointments
EMOLLIENTS
Other, more specialised treatments available for psoriasis?
Phototherapy (narrowband UVB and PUVA)
Systemic treatments, such as immunosuppression and immune modulation (with targeted biologic agents)
What is acne vulgaris and how does it develop?
Chronic inflammatory disease of the pilosebaceous unit; there is increased sebum production and poral occlusion
Bacterial colonisation of the duct occurs, by P. acnes, and this is followed by dermal inflammation
Distribution of acne vulgaris?
Related to sites with the most sebaceous glands, i.e: face, upper back and chest
Morphology of acne vulgaris?
Comedones - open (blackhead) and closed (whitehead)
Pustules and papules
Cysts
Erythema
Secondary features of acne vulgaris?
Different types of scarring: Atropic Hypertrophic Ice-pick Texture changes
Grading of acne?
Mild - scattered papules, putules and comedones
Moderate - numerous papules and pustules along with mild atrophic scarring
Severe - cysts, nodules and significant scarring
First-line therapies for acne vulgaris?
Topical agents, e.g: keratolytics (benzoyl peroxide) or topical retinoids (isotretinoin)
For inflammatory acne, topical antibiotics are used, e.g: erythromycin or clindamycin
Second-line therapies for acne vulgaris?
Low-dose oral antibiotic therapy
Third-line therapies for acne vulgaris?
Oral retinoid drugs, e.g: oral isotretinoin, if:
All other measures have failed
Nodulocystic acne with scarring
Severe psychological disturbance
What are retinoids?
Synthetic vitamin A analogues that affect cell growth and differentiation
Side effects of oral retinoids?
Inital aggravation of acne
Very teratogenic - person must be on oral contraceptive or not sexually active (pregnancy test before and monthly during treatment)
What is rosacea?
Common inflammatory rash predominantly affecting the face, part. nose, chin, cheeks and forehead
Onset is normally in middle-ages and is more common in women
Describe the rash in rosacea
Papules, pustules and erythema but no comedones (i.e: this is NOT a disease of the pilosebaceous units)
Triggers of rosacea?
Exacerbated by sudden changes in temp, alcohol and spicy food
Other symptoms of rosacea?
Rhinophyma (enlarged nose)
Conjunctivitis/gritty eyes
Management of rosacea?
Reduce aggravating factors, e.g: dietary triggers, sun exposure and AVOID TOPICAL STEROIDS (can worsen the skin)
Topical therapies, e.g: metronidazole, to reduce the demodex mites
Oral therapies, e.g: long-term oral tetracycline and, if severe, isotretinoin (low dose)
Vascular lasers for telangiectasia
Surgery/laser shaving for rhinophyma
Characteristics of lichenoid eruptions?
Damage and infiltration between the epidermis and dermis
Most common types of lichenoid eruptions?
Lichen planus
Lichenoid drug eruptions, e.g: ACE inhibitors (normally, a delayed reaction), statins, etc
Clinical presentation of lichen planus?
Violaceous (pink/purple), flat-topped shiny papules typically affecting volar wrists/forearms, shins and ankles
Wickham’s striae (fine, white lace pattern on papule surface and on the buccal mucosa)
Intensely pruritis
Occurrence of lichen planus?
Tends to occur in middle age and lasts around 12-18 months before burning out
Treatment of lichen planus?
Treat symptomatically: Topical steroids (if extensive, oral) - these should be potent/very potent
How to differentiate between bullous pemphigoid and pemphigus?
Bullous pemphigoiD:
Split is Deeper, through DEJ
PemphiguS:
Split more Superficial, intra-epidermal
What is Nikolsky’s sign?
Top layers of the skin slip away from the lower layers when slightly rubbed; this indicates a PLANE OF CLEAVAGE WITHIN THE EPIDERMIS , i.e: when the skin is rubbed, exfoliation of the outer layers can occur
Present in Pemphigus vulgaris and Toxic Epidermal Necrolysis, but not in bullous pemphigoid
Clinical presentation of bullous pemphigoid?
Localised to one area/widespread on the trunk and proximal limbs
There are large, TENSE, BULLAE on an erythematous base; these can burst and leave erosions that do not scar
However, early in disease, there may be urticated itchy plaques rather than bullae
Nikolsky sign (negative) and mucosal lesions are unlikely
Clinical presentation of pemphigus vulgaris?
Flaccid vesicle/bullae (thin-roofed) typically affecting the scalp, face, axillae and groin
Lesions rupture to leave raw areas (infection risk)
Nikolsky sign +ve and mucosal involvement is very common, e.g: eyes, genitals
Prognosis of pemphigus vulgaris?
Chronic self-limiting course but the duration varies from months-years
Most patients achieve REMISSION on treatment within 3-6 months
Difference between mortality of pemphigus and bullous pemphigoid?
If untreated, pemphigus has a very high mortality
Bullous pemphigoid has much lower risk
Investigations for pemphigus or bullous pemphigoid?
Skin biopsy with direct immunofluorescence
Indirect immunofluorescence
Treatment of pemphigoid and pemphigus?
Systemic steroids
Other immunosuppressive agents
Topicals, such as emollients, topical steroids, topical anti-sepsis/hygiene measures
IN PEMPHIGOID - tetracycline antibiotics
