Skin Disorders Flashcards
What is psoriasis?
chronic, immune-mediated disorder
What causes psoriasis?
polygenic predisposition + environmental triggers e.g., trauma, infections, or medications
What characterises psoriasis?
Sharply demarcated, scaly, erythematous plaques characterise the most common form of psoriasis
Common sites of involvement are scalp, elbows and knees, followed by nails, hands, feet and trunk (including intergluteal fold)
What is the most common systemic manifestation of psoriasis?
psoriatic arthritis
What is the pathophysiology of psoriasis?
● Stressed keratinocytes release DNA / RNA
→ form complex with antimicrobial peptides
→ induce cytokines (TNF-α, IL-1 and IFN-α) production
→ activate dermal dendritic cells (dDCs)
● dDCs migrate to lymph nodes → promote Th1, Th17, Th22 cells
→ chemokine release – migration of inflammatory cells into dermis
→ cytokine release
→ keratinocyte proliferation
→ psoriatic plaque
What can psoriasis look like in more pigmented people?
more brown
What are the methods of management of psoriasis?
Lifestyle
therapeutic ladder
phototherapy
medicine
systemic immunosuppression
advanced therapies
What do we mean by lifestyle for management of psoriasis?
Alcohol and smoking
co-morbidities
What is meant by therapeutic ladder for management of psoriasis?
● Topical therapies
➢ Vitamin D analogues
➢ Topical corticosteroids
➢ Retinoids
➢ Topical tacrolimus / pimecrolimus
What is phototherapy?
intentional daily exposure to direct sunlight or similar-intensity artificial light in order to treat medical disorders.
Narrowband UVB
PUVA (psoralen + UVA)
What is narrowband UVB?
A specific wavelength of UVB (311 to 312 nanometers) is thought to be the most useful range for treating skin conditions.
What is PUVA?
PUVA is an ultraviolet light therapy treatment for skin diseases
What medication can be used to treat psoriasis?
Acitretin (retinoid)
What are retinoids?
chemicals derived from vitamin A
What systemic immunosuppression can be used to manage psoriasis?
Methotrexate
Ciclosporin
What advanced therapies can be used to manage psoriasis?
PDE4 inhibitors (Apremilast)
Biologics (anti-TNF-α, anti-IL-17, anti-IL-23)
JAK inhibitors
What else do JAK inhibitors treat?
arthritis
What is atopic eczema?
Intensely pruritic chronic inflammatory condition
Complex genetic disease with environmental influences
When does atopic eczema typically begin?
Typically begins during infancy or early childhood
What is atopic eczema often associated with?
other ‘atopic’ disorders e.g., asthma, rhinoconjunctivitis
What are characteristics of atopic eczema?
Acute inflammation of cheeks, scalp, and extensors in infants
Flexural inflammation and lichenification in children and adults
What is lichenification?
thickening of the skin
What is the management of atopic eczema usually like?
Daily emollients and anti-inflammatory therapy are cornerstone of management
What is another word for eczema?
dermatitis
What is eczema an umbrella term for?
atopic eczema, seborrheic dermatitis, venous stasis eczema, allergic contact dermatitis, irritant contact dermatitis
What are the 2 parts of pathophysiology of eczema?
● Barrier defect
and
● Immune dysregulation
what are Corneocytes?
Terminally differentiated keratinocytes and compose most of the stratum corneum
Explain the barrier defect?
● Barrier defect
➢ Filaggrin - bind and aggregate keratin bundles &
intermediate filaments → form cellular scaffold in corneocytes
➢ Reduced extracellular lipids & impaired ceramide production
➢ Increased transepidermal water loss (TEWL)
➢ Impaired protection against microbes and
environmental allergens
Explain the immune dysregulation?
● Immune dysregulation
➢ Staphylococcal superantigens stimulate Th2
lymphocyte responses and subvert T-reg
➢ T-cell infiltrate - bias towards Th2 responses
➢ Role of microbiome?
➢ Eosinophils
How would you describe the mediation of eczema?
Th2 mediated diseases
What are the clinical features of infantile phase of atopic dermatitis?
erythematous, oedematous, papule and plaques +/- vesiculation
What are the clinical features of eczema?
lichenification, crusting, excoriation and dyspigmentation, postinflammatory dyspigmentation, fissuring, allergic contact dermatitis, impetiginisation
What is impetiginization?
secondary infection of a lesion by bacteria, usually by virtue of animated scratching.
- gold crust
- staphylococcus aureus
What is the gold crust in impetiginisation?
shows it’s a superficial infection
the crust is cellular and bacterial debri (inflammatory infiltrate)
What is the difference between scale and crust?
crust is cellular and bacterial debri
scale is keratin
Where do you see scales?
Psoriasis
What is venous stasis eczema?
Swelling of skin due to compromise of venous blood going back to the heart
It is treated with compression
It leads to water loss
What is eczema herpeticum?
- emergency
- HSV (herpes simple virus)
- treat with acyclovir
- can lead to permanent neurological disease
- looks like monomorphic punched out erosions
What is eczema herpeticum often mistaken for?
for aggravation of eczema
What is erythroderma?
skin failure
What are the managements for eczema?
Lifestyle
-Emollients
-Omission of soap
Clinical Nurse Specialist involvement
- Topical application technique
- Day treatment
- Habit reversal
Co-morbidities
Patch testing
Biopsy
Topical therapies
Phototherapy
Topical immunomodulators
Retinoids
Systemic immunosuppression
Advanced therapies
When do you need a biopsy?
When there is persistent nipple eczema, it can manifest into breast cancer
What happens when you itch?
itching causes release of cytokines leading to more itching
What are the therapeutic ladder methods of managing eczema?
Topical therapies
Topical corticosteroids - correct potency for correct site
Topical tacrolimus / pimecrolimus
What are phototherapy methods of managing eczema?
Narrowband UVB
PUVA (hand dermatitis)
What is important about topical immunomodulators for eczema?
● Important role in management of eczema
● Potential for:
➢ Underuse (poor adherence)
➢ Overuse of topical corticosteroids (tachyphylaxis / adverse effects)
● Counselling crucial:
➢ Correct steroid for correct site (steroid ladder)
➢ Adverse effects
➢ Amount to use – Fingertip unit
What is the order of drugs in the steroid ladder?
hydrocortisone is safer for delicate areas like the face, neck and genitals
Clobetasol can be used for palms and soles
What are adverse effects of topical corticosteroids?
● Adverse effects of topical corticosteroids:
➢ Rare: skin atrophy, folliculitis, exacerbation of acne and rosacea, infection
➢ Very rare: perioral dermatitis (right), rebound syndrome (tachyphylaxis), allergy (to steroid itself or vehicle)
➢ Extremely rare: hormonal imbalance (suppression of hypothalamic-pituitary- adrenal axis), hirsutism
What are the adverse effects of topical calcineurin?
burning sensation
What type of dermatitis are retinoids used for?
hand
What systemic immunosuppression can be used for eczema?
➢ Methotrexate
➢ Ciclosporin
➢ Azathioprine
➢ Mycophenolate mofetil
What advanced therapies can be used for eczema?
➢ Biologics (anti-IL-4α, anti-IL13)
➢ JAK inhibitors
Overall what are the types of atopic eczemas you need to know?
erythroderma
herpeticum
venous stasis
allergic contact
