ICADA Skin Barrier Flashcards
Issues with TEWL, an INDIRECT measurement of skin barrier function (3)
*Room temperature
*Humidity
*Inter/intraobserver variability
3 indirect measurements of skin barrier function that may be more reliable than TEWL
1) Corneometer (skin hydration)
2) pH meter
3) Colorimeter (erythema)
**Ideally: use above 3 in conjunction with vapometer for TEWL
Which 2 skin barrier measurement modalities correlate with disease severity
*TEWL (more water loss = more severe dz)
*pH (more basic pH = more severe)
How are ceramide levels in cAD dogs compared to healthy dogs?
Lower ceramides in cAD
Which ceramides are decreased in cAD dogs?
1) Ceramide 1 (CER[EOS])
2) Ceramide 9 (CER[EOP])
3) Ceramide (CER[NP])
How is the stratum corneum organized in atopic dogs?
Hexagonal lipid packing
How is the stratum corneum organized in normal, healthy dogs
Orthorhombic packing
Which ratio of ceramides is decreased in cAD dogs?
CER[NS] C44/C34
Lower ratio = more severe cAD
Which dogs have a filaggrin SNP mutation associated with their cAD
Labrador retrievers in the UK
Do most dogs with cAD have mutations in filaggrin?
No
Why does Santoro think studies evaluating filaggrin in cAD dogs may be flawed?
Potentially were investigating Filaggrin 2, rather than filaggrin.
Filaggrin 2 is a component of cornified envelope, makes NMF
Which enzymes are changed in nonlesional cAD dogs, compared to healthy dogs?
*Decreased Caspase-14 in cAD in 1 study
*Increased Caspase-14, Matriptase, Calpain-1 in another study
Which proteins are decreased in cAD? (6)
*Claudin-1 (tight junction)
*Occludin (tight junction)
*Corneodesmosin
*E-cadherin (adherens junction)
*Desmocollin-1
*Desmoglein-1
What are the 2 major microorganisms that are increased in cAD microbiome dysbiosis?
*Staphylcococcus pseudintermedius
*Malassezia pachydermatis
Which bacterial phyla are present in both healthy and cAD dogs, but increased in cAD skin?
*Actinobacteria
*Proteobacteria
*Firmicutes
*Bacteroidetes
*Tenericutes
Which Malassezia sp is predominant in healthy skin?
Malassezia globosa
Which Malassezia sp is predominant in cAD skin?
Malassezia pachydermatis
How long after allergy challenge does increase in abundance of Corynebacteria and Staphylococcus persist for?
2 weeks after remission of skin lesions
Right after resolution of pyoderma treatment, how does the cAD skin microbiome compare to healthy skin?
Goes back to normal for 4 weeks!
However, decreased diversity recurs within 4-6 weeks
Which bacteria have increased abundance in the external ear canal of cAD dogs?
*Staphylcococcus (Firmicutes)
*Ralstonia (Proteobacteria)
Which bacteria have an increased abundance in HEALTHY external ear canals compared to cAD?
Escherichia sp
Most common microbial SPECIES on healthy skin?
(Tang et al 2020)
*Cutibacterium acnes
*S. pseudintermedius
*Porphyromonas cangingivalis
*Capnodiales (unclassified fungal species)
*Alternaria sp
Most common microbial SPECIES on cAD skin
(Tang et al 2020)
*S. pseudintermedius
*S. schleiferi
*Bacteriodes pyogenes
*Peptoniphilus grossensis
Most common microbes in healthy ears
(Tang et al 2020)
*Cutibacterium acnes
*S. pseudintermedius
*Streptococcus sp.
*M. pachydermatis
*Capnodiales (fungal)
*Pleosporales (fungal)
