Rash disease profiles Flashcards
Psoriasis, Lichenoid disorders, immunobullous disorders, acne, rosacea
What is the cause of psoriasis
Unknown
What is the pathological process of psoriasis?
Increased epidermal turnover
What is the Koebner phenomenon?
Production of new lesions at sites of trauma
How is psoriasis described?
Well demarcated, silvery plaques with erythema underneath (due to blood vessels being closer to the surface)
What is the most common type of psoriasis?
Chronic plaque psoriasis // psoriasis vulgaris
Which sites of psoriasis most commonly found on?
Extensor surfaces
What other systemic effects can psoriasis have?
Nail changes and joint pain
How is psoriasis diagnosed?
Clinically based upon appearance and location
What is the main stay of psoriasis management?
Emollients
What type of psoriasis affects the whole body?
Guttate psoriasis
What is the clinical presentation of lichenoid disorders?
Very itchy papules
Where do lichenoid disorders typically affect?
Wrists/forearms + shins/ankles, often has mucosal symptoms
What is sign on histology of lichenoid disorders?
Saw tooth pattern (notching) of the dermis into the epidermis, thickened epidermis
How are lichenoid disorders diagnosed?
Clinical diagnosis with confirmation on histology
How are lichenoid disorders treated?
Self limiting (12-18 months)
Give potent or very potent steroids
If widespread, oral steroids
What is the cause of pemphigus and pemphigoid conditions?
Autoimmune blistering conditions
What is the difference between the bull produced in pemphigus and pemphigoid?
Pemphigus = think and flaccid Pemphigoid = large and tense
Which layer of the skin is affected in pemphigus vs pemphigoid?
Pemphigus: epidermal cell adhesion (superficial)
Pemphigoid: sub-epidermal (deep)
What is acantholysis and which immunobullous disorder exhibits this?
Lysis of intercellular adhesion sites
Pemphigous
How are immunobullous disorders diagnosed?
Skin biopsy with immunofluorescence for autoantibodies
How are immunobullous disorders treated or managed?
Management: emollients/topical steroids
Treatment: systemic steroids/immunosuppressive agents
Self limiting in months - years
What is the pathophysiology of acne?
Increased androgen during puberty
Increased sebum and keratin production
Plugs polo-sebaceous unit
Bacterial infection
How is acne managed/treated?
Avoid oily substances or other triggers
Topical: retinoids (dry out skin), antibiotics (antibacterial + anti-inflammatory effects)
Oral: antibiotics + isotretin (oral retinoid)
What is the clinical presentation of rosacea?
Erythema across cheeks and forehead, pustules, thickened skin, enlarged nose
Aggravated/stimulated by sunlight, spicy foods, stress, alcohol
How is rosacea treated/managed?
Topical metronidazole
If severe; oral tetracycline or low dose isotretin
Which disease is dermatitis herpetiformis associated with?
Coeliac
How to eczema present?
Itchy, erythematous, ill-defined scaly lesions
What pathological changes are seen in eczema?
Spongiosis with inflammatory infiltrates
What is the difference between contact allergic dermatitis and irritant dermatitis?
Contact allergic dermatitis: specific immune response to an allergen
Irritant dermatitis: non-specific immune response to a repeated stimulus from an irritant
What is the main stay of eczema treatment?
Emollients
What is eczema herpeticum and what is the typical presentation?
Herpes simplex virus infection, presents as monomorphic punched out lesions
What causes stasis eczema?
Increased hydrostatic pressure in the legs
