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<big><center>[[Skin Congenital and Hereditary - Pathology#Porcine Juvenile Pustular Psoriasiform Dermatitis|'''BACK TO SKIN - CONGENITAL''']]</center></big>

*-> lesions join and spread -> umbilicated [[Skin Glossary - Pathology|plaques]] containing white centres with erythematous and scaly borders

**Epidermal hyperplasia, [[Skin Glossary - Pathology|parakeratosis]], epidermal [[Skin Glossary - Pathology|pustules]] and superficial perivascular dermatitis

*For more detail see [[Porcine Juvenile Pustular Psoriasiform Dermatitis]]

==Porcine Juvenile Pustular Psoriasiform Dermatitis (Pityriasis rosea)==

==Porcine Juvenile Pustular Psoriasiform Dermatitis (Pityriasis rosea)==

===General===

===General===

*Pityriasis rosea is a self‑limiting inflammatory disease of young pigs.   

*Pityriasis rosea is a self‑limiting inflammatory disease of young pigs.   

*The condition most frequently occurs in young pigs, 3‑14 weeks of age, and often more than one member of a litter is affected.

*The condition most frequently occurs in young pigs, 3‑14 weeks of age, and often more than one member of a litter is affected.

*'''Although this condition had been previously called pityriasis rosea, clinically and pathologically it is nothing like pityriasis rosea in humans!'''

*'''Although this condition had been previously called pityriasis rosea, clinically and pathologically it is nothing like pityriasis rosea in humans!'''

===Clinical Signs===   

===Clinical Signs===   

*There are usually no systemic signs.  Skin lesions may be preceded by anorexia, vomiting, & diarrhea.   

*There are usually no systemic signs.  Skin lesions may be preceded by anorexia, vomiting, & diarrhea.   

*There is no fever.

*There is no fever.

===Gross Lesions===

===Gross Lesions===

*Primary lesions are seen on the ventral abdomen or medial thighs, and appear as symmetric, sharply defined, red raised plaques up to 6 mm in diameter.   

*Primary lesions are seen on the ventral abdomen or medial thighs, and appear as symmetric, sharply defined, red raised plaques up to 6 mm in diameter.   

**The term pseudo-ringworm has been used to describe this condition.   

**The term pseudo-ringworm has been used to describe this condition.   

*Lesions are nonirritant and usually resolve spontaneously in 2 ‑ 10 weeks.

*Lesions are nonirritant and usually resolve spontaneously in 2 ‑ 10 weeks.

===Microscopic Lesions===

===Microscopic Lesions===

*Skin biopsy reveals superficial perivascular dermatitis with psoriasiform epidermal hyperplasia.   

*Skin biopsy reveals superficial perivascular dermatitis with psoriasiform epidermal hyperplasia.   

*The superficial dermis usually shows mild to moderate mucinous degeneration, and eosinophils and neutrophils are the predominant inflammatory cell types.   

*The superficial dermis usually shows mild to moderate mucinous degeneration, and eosinophils and [[Neutrophils|neutrophils]] are the predominant inflammatory cell types.   

*Intra-epidermal pustules containing eosinophils and neutrophils are prominent in early lesions.   

*Intra-epidermal pustules containing eosinophils and [[Neutrophils|neutrophils]] are prominent in early lesions.   

*Parakeratotic hyperkeratosis is usually prominent.

*Parakeratotic hyperkeratosis is usually prominent.

===Differential Diagnosis===

===Differential Diagnosis===

#Dermatophytosis ‑ (etio: Tr. mentagrophytes, M. canis, Tr. verrucosum var. discoides, M. nanum, Tr. rubrum) Ruled‑out due to lack of mycotic organisms.

#Dermatophytosis ‑ (etio: Tr. mentagrophytes, M. canis, Tr. verrucosum var. discoides, M. nanum, Tr. rubrum) Ruled‑out due to lack of mycotic organisms.

#[[Skin - infectious#Greasy pig disease|Exudative epidermitis (greasy pig disease)]] ‑ (''Staphylococcus hyicus'') Early lesions may appear as red plaques, but soon become exudative and ulcerated; R/O based on culture, lesion distribution, histopathology.

#[[Skin Infectious - Pathology#Greasy pig disease|Exudative epidermitis (greasy pig disease)]] ‑ (''Staphylococcus hyicus'') Early lesions may appear as red plaques, but soon become exudative and ulcerated; R/O based on culture, lesion distribution, histopathology.

#Dermatosis vegetans ‑ Systemic, erythematous maculopapular dermatitis caused by the inheritance of a autosomal recessive, semilethal factor.  Skin, coronary band and hoof lesions, giant cell pneumonia, fatal.

#Dermatosis vegetans ‑ Systemic, erythematous maculopapular dermatitis caused by the inheritance of a autosomal recessive, semilethal factor.  Skin, coronary band and hoof lesions, giant cell pneumonia, fatal.

#Swinepox ‑ Ballooning degeneration and intracytoplasmic inclusion bodies.

#Swinepox ‑ Ballooning degeneration and intracytoplasmic inclusion bodies.

===Postgraduate===

===Postgraduate===

Kate

Kate

::''IL-3 is involved... Vet Path (2007)  34: 45-43''

::''IL-3 is involved... Vet Path (2007)  34: 45-43''