Difference between revisions of "Stephanofilariasis"
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| − | *Caused by [[Stephanofilaria | + | *Caused by [[Stephanofilaria stilesi|''Stephanofilaria stilesi'']] |
*Occurs in cattle, buffalo, goats | *Occurs in cattle, buffalo, goats | ||
*Transmitted by [[Insecta|flies]] | *Transmitted by [[Insecta|flies]] | ||
| Line 11: | Line 11: | ||
**[[Skin Glossary - Pathology|Epidermal hyperkeratosis, parakeratosis, acanthosis]], eosinophilic microabscesses and crusts | **[[Skin Glossary - Pathology|Epidermal hyperkeratosis, parakeratosis, acanthosis]], eosinophilic microabscesses and crusts | ||
| + | ===Gross pathology=== | ||
| + | *Lesions begin as small circular patches on the ventral midline with serous exudate. | ||
| + | *These enlarge and coalesce producing lesions 25cm or more in diameter. | ||
| + | *Hemorrhage develops along the periphery while the older, central areas develop scabs or dry crusts. | ||
| + | *Healing lesions are alopecic, lichenified plaques. | ||
| + | *Lesions may also occur on the flank, udder, teats, face and neck. | ||
| − | [[Category:To_Do_- | + | |
| + | |||
| + | ===Histopathology=== | ||
| + | *Adult parasites occur within cystic diverticula of hair follicles or free within the adjacent dermis. | ||
| + | **Parasites may have lateral cords and lateral cuticular projections. | ||
| + | **The thick intestine is distinctive. | ||
| + | **Microfilariae within uteri is the key feature. | ||
| + | ***Microfilariae also occur free within the dermis, in dermal lymphatics, or in the surface exudate. | ||
| + | *There is little dermal reaction to adults in cystic hair follicles, but their presence within the dermis elicits eosinophilic and mononuclear inflammation. | ||
| + | |||
| + | ===Differential diagnosis=== | ||
| + | # Pelodera strongyloides: | ||
| + | #*Rhabditid parasite, adults 1-1.5mm long, found in follicles | ||
| + | #*uteri contain eggs, not microfilaria. | ||
| + | # Dermatophytosis (Trichophyton verrucosum is most common) | ||
| + | # Mange (Chorioptes bovis) | ||
| + | # Fly bite dermatitis | ||
| + | # Contact dermatitis | ||
| + | # Zn-responsive dermatitis | ||
| + | # Other subcutaneous filarid parasites: | ||
| + | #*Parafilaria bovicola (adult worms 30-70mm long, found coiled in nodules in subcutaneous and intramuscular connective tissues; not seen in US) | ||
| + | #*Onchocerca gutterosa (adult worms 60mm long, found in nuchal ligament and subcutaneous connective tissues). | ||
| + | |||
| + | {{unfinished}} | ||
| + | [[Category:Integumentary System - Helminth Infections]] | ||
| + | [[Category:To_Do_-_Dermatology]][[Category:To Do - Minor]] | ||
Latest revision as of 17:38, 20 July 2011
- Caused by Stephanofilaria stilesi
- Occurs in cattle, buffalo, goats
- Transmitted by flies
- Affects ventral midline (other species affect different areas of body)
- Grossly:
- Foci extending to large areas
- Errect hairs, epidermal haemorrhage, serum exudate -> crusts
- Microscopically:
- Superficial and deep perivascular dermatitis
- Eosinophils, adult and microfilarial parasites
- Epidermal hyperkeratosis, parakeratosis, acanthosis, eosinophilic microabscesses and crusts
Gross pathology
- Lesions begin as small circular patches on the ventral midline with serous exudate.
- These enlarge and coalesce producing lesions 25cm or more in diameter.
- Hemorrhage develops along the periphery while the older, central areas develop scabs or dry crusts.
- Healing lesions are alopecic, lichenified plaques.
- Lesions may also occur on the flank, udder, teats, face and neck.
Histopathology
- Adult parasites occur within cystic diverticula of hair follicles or free within the adjacent dermis.
- Parasites may have lateral cords and lateral cuticular projections.
- The thick intestine is distinctive.
- Microfilariae within uteri is the key feature.
- Microfilariae also occur free within the dermis, in dermal lymphatics, or in the surface exudate.
- There is little dermal reaction to adults in cystic hair follicles, but their presence within the dermis elicits eosinophilic and mononuclear inflammation.
Differential diagnosis
- Pelodera strongyloides:
- Rhabditid parasite, adults 1-1.5mm long, found in follicles
- uteri contain eggs, not microfilaria.
- Dermatophytosis (Trichophyton verrucosum is most common)
- Mange (Chorioptes bovis)
- Fly bite dermatitis
- Contact dermatitis
- Zn-responsive dermatitis
- Other subcutaneous filarid parasites:
- Parafilaria bovicola (adult worms 30-70mm long, found coiled in nodules in subcutaneous and intramuscular connective tissues; not seen in US)
- Onchocerca gutterosa (adult worms 60mm long, found in nuchal ligament and subcutaneous connective tissues).
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This article is still under construction. |