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| *Healing lesions are alopecic, lichenified plaques. | | *Healing lesions are alopecic, lichenified plaques. |
| *Lesions may also occur on the flank, udder, teats, face and neck. | | *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). |
| | | |
| ==Stephanofilaria assamensis== | | ==Stephanofilaria assamensis== |