Eczema, prurigo, LSC, PsO Flashcards
List pathophys factors for AD
Genetic - fillagrin (AD) Genetic - immune dysfunction syndromes (PAWHANAH) Immune dysregulation - Th2 cell mediated - IL13, IL4, IL31 Hygiene hypothesis Atopic march Environmental - allergens/irritants Microbiome, gut flora Food allergy Breastfeeding Barrier dysfunction Infection - staph, HSV Pruritus, scratching induced skin dammage + inflammation (itch scratch cycle) Climate Stress
ATopic dermatitis associations
ASthma, hay fever, allergic rhinitis, food allergy, contact dermatitis
Autoimmune - vitiligo, AA, chronic urticaria, RA, IBD, coeliac, thyroid
Clinical features of AD
Fillagren mutation (hyperlinear palms, ichthyosis, KP)
ITCH is key for all + erythema, lichenification, oedema/induration, excoriation
Subdivide into age groups:
- infants - (<2 years) - initially on cheeks, then becomes extensor surfaces before flexural; sparing of napkin area (moisture)
- children - flexural pattern, atopic dirty neck (reticulate pigmentation)
- adults similar to late childhood - lichenification
What are the severity scores for AD
SCORAD, EASI, global score, DLQI
Explain EASI
Score H+N, UL, Trunk, LL
- Erythema, Oedema, Lichenification, Excoriation (0-3)
- x site factor (0.1, 0.2, 0.3, 0.4)
- area % - 0, 1-9, 10-29, 30-49, 50-69, 70-89, 90-100
Explain SCORAD
A, B + C scores (A/5 + 7B/2 + C)
A = total % SA (rule of 9s)
B = 0-3 score for representative area (RO SOLD - Red, ooze, scratch, oedema, lichenification, dryness)
C= VAS for itch 0-10
Complications of AD
- Psychological, poor sleep, poor concentration, depression, suicidality, poor self-esteem, social isolation
- stunted growth
- medication complications - steroid induced/ immunosuppression
- infection (staph, strep, HSV, molluscum, warts)
- non-cutaneous infections - strep throat, UTI, endocarditis, otitis
- ocular - blepharitis, conjunctivitis, keratoconjunctivitis, keratoconus, cataracts, glaucoma
- lymphoma
- food allergy, contact dermatitis
- AA, urticaria
Prognosis of AD including prognostic factors
-60% childhood cases resolve by adolescence
- 25% of cases will relapse though during adulthood
- In general:
– persistent (20%)
– intermittent (40%)
– remitting (40%)
Poor Prog Factors:
- early onset
- severe disease
- poorly controlled disease
- FHx atopy
- high IgE
- fillagrin mutation
What Ix in AD?
Bx if unclear Swabs/scrapings IgE, RAST/specific IgE Skin prick testing Allergy patch testing Pre-tx investigations
Any ways of minimising risk of AD in an infant?
No evidence for pregnancy diet, duration of breastfeeding etc
Just daily emollients from birth
General mx considerations in AD
Education
Photographs
Liaise w GP
Support psychology/ support groups
Modify triggers (heat, stress, allergy/irritant contact, infection, environment)
Address sleep + itch (antihistamines, behavioural)
General measures (soap avoidance, regular emollient)
Treat secondary infection, maintainance antimicrobial (nasal, bleach, condys)
Ocular
Skin topicals - TCS, tacrolimus, JAK, PDE4 (crisaborole)
Wet wrap
skin physical - ILCS, nbUVB, UVA-1
skin systemics - Pred, CsA, MMF, Mtx, Aza, dupilumab, omalizumab, ustekinumab, bunch of newbies
Follow up, monitor complications
Biologics in AD
Dupilumab (4, 13) Omalizumab (little evidence) Ustekinumab (variable ev) baricitinib (JAK) nemolizumab (IL31) lebrikizumab (IL13) tralokinumab (IL13) fezakinumab (IL22)
Diagnostic criteria for AD
itchy skin + 3 or more of: OCDAF - onset < 2 years - Crease involvement/cheeks - dry skin - atopy - flexural dermatitis
Consider excluding immunodefiency in setting of eczema if:
FETALL POO failure to thrive erythroderma Thrombocytopenia Alopecia Lymphopenia Large + multiple LNs Parental cosanguinity Onset in neonatal period Opportunistic infection
What is the maximum EASI score?
72
PASI also 72 max score
Approach to pruritus in CKD patients - Mx
general skin measures parathyroidectomy if high PTH phototherapy reduce phosphate/ normalise Ca/Phosphate balance topical capsaicin topical tacrolimus thalidomide
Approach to pruritus in hepatobiliary disease
Note that can be localised hands/feet general measures Phototherapy cholestyramine, ursodeoxycholic acid naltrexone sertraline
Features of itch associated w PCV
aquagenic (onset 15-60 mins exposure to water)
Pruritic screen
Skin bx + DIF +/- culture FBC ELFTs Iron studies TFTs IgE anti-skin ab's serum EPP, blood film Strongyloides Hep B/C LDH Glucose Age-appropriate malignancy screen Other - ANA, tryptase, PTH, calcium, coeliac abs, H pylori
General measures for itchy patient
Avoid triggers (dry skin, irritants, hot/spicy food, alcohol, stress) Soap free wash Lukewarm shower (not hot), not prolonged soft permeable clothing regular moisturiser urea, menthol wet/cool wraps
Symptomatic tx for pruritic patients
TCS, topical calcineurin ILCS Topical doxepin Phototherapy Antihistamines Doxepin Naltrexone Thalidomide
Mx prurigo nodularis
General measures TCS, calcinurin, calcipotriol capsaicin 0.025% phototherapy systemic anti-itch/ psych naltrexone Thalidomide gabapentin SSRIs/ SNRIs Immunomodulatory (CsA, mtx) Nemolizumab (IL31) Topical ketamine 5-10% + amitriptyline 5% + lidocaine 5%
Epidemiology of chronic plaque psoriasis
Bimodal - 16-22 + 57-62
M=F though M more likely to have severe disease
Genetics of Psoriasis
PSORS1-9 (majority PSORS1 on chromosome 6p)
HLA-C = major risk allele (MHC class I antigen)
CARD14 (clinical overlap PsO + PRP - CARD14-associated papulosquamous eruption)
