Ichthyosis

Question 1

General Ichthyosis

Answer 1

Rare congenital disorders caused by primary defects in formulation of the stratum corneum.

Subdivided: epidermolytic vs nonepidermolytic

Biopsy for diagnosis

Question 2

Epidermolytic ichthyosis

Answer 2

Defect in Keratin formation
Multi focal regions of pigmented scale with alopecia and roughening of skin

Norfolk terriers (autosomal recessive)
Sporadic in other breeds:  Rhodesian Ridgeback, Lab cross

Question 3

Nonepidermolytic Ichthyosis

Answer 3

Autosomal recessive traits
Characterization in dogs still in infancy

Current nomenclature used by pathologist - by breed predilection

Question 4

Golden Retriever Ichthyosis

Answer 4

More common as compared to other ichthyosis forms
Mild form of scaling
White to gray adherent scale prominent on trunk
May have ventral hyperpigmentation
Typically diagnosed under 1 year of age
Disease may wax and wane
Biopsy for diagnosis
Genetic test used to screen breeders - PNPLA1 gene

Question 5

American Bulldog Ichthyosis

Answer 5

Clinical signs develop before weaning
Scruffy, disheveled hair coat
Skin is erythematous with tight adherent brown scales
Abdomen appears wrinkled, reddish brown colored in adults
Development of Malassezia, otitis external and pododermatitis common
Condition does not improve
Genetic test: NIPAL-4 for carriers

Question 6

Jack Russell Terrier Ichthyosis

Answer 6

Caused by loss of function mutation in transglutaminase 1 (TGM1)
Large, thick, adherent, parchment paper like scales
More severe than Golden Retriever or Bulldog ichthyosis
Severe Malassezia infections can occur

Question 7

Treatment

Answer 7

No cure, only management
Topical therapy TOC
Keratolytic agents to remove excessive scale
Moisturizers to restore skin barrier, prevent water loss
Topical anti microbial (miconazole) for secondary bacteria or yeast infections
Baths every other day - twice weekly
Shampoos containing 2% sulfur and salicylic acid
Allen Derm spot on with fatty acids
Antifungals oral for 21 days may be needed for Malassezia infections

Question 8

Vitamin A Responsive Deramtosis

Answer 8

Primary DOC (disorders of cornification)
Adult Cocker Spaniels most common
Greasy hair oats
Skin biopsy to diagnose
Treatment - Vitamin A 10,000 IU/day
Response seen in 3 - 8 weeks, life long therapy may be needed