bovis - Articles
Contact dermatitis
Synonym(s): Irritant, allergic
Introduction
- Cause: may be irritant contact dermatitis (more common) or allergic contact dermatitis (rare).
- Signs: variable pruritus and pain, erythema, macules, papules, pustules, edema, vesicles, crusts in contact areas with reduced hair cover.
- Diagnosis: removal of contact irritant leads to resolution.
- Treatment: eliminate irritant from environment.
- Prognosis: good.
Pathogenesis
Etiology
- Cement dust, freshly laid cement, plaster dust, acids and alkalis, corrosive substances eg waste motor oil.
- Weed and insecticidal sprays, fertilizers eg nitrolime (calcium cyanamide).
- Cleaning products (soaps, shampoos, detergents, disinfectants).
- Some plants eg Commelinanceae family including Tradescantiae, also Urtica spp, Helenium, Euphorbia, Cleome, Digitalis (foxglove)
, Pteridium (bracken)
Bracken fern poisoning.
- Urine, feces and wound secretions.
- Preservatives, dyes and polishes eg on head collars, calf jackets, harnesses for draught animals.
- Plastics and rubber eg calves fed milk replacer from buckets.
- Wood preservatives eg creosote.
- Bedding, such as treated wood products, paper waste, 'green' bedding (treated manure), sand etc.
Predisposing factors
General
- Increased moisture decreases the normal barrier function of the skin allowing closer contact of the irritant or allergenic substance to the skin surface.
- Prolonged immersion in water, urine and fecal contamination of skin and excessive sweating all predispose.
- Sparsely haired body areas predisposed eg muzzle, face, lower limbs, perineum and ventrum.
Pathophysiology
- Irritant contact dermatitis caused by prolonged skin contact with irritant substances in sufficient concentration to cause dermatitis in all individuals without immunological mediation.
- Allergic contact dermatitis caused by type IV hypersensitivity reaction where antigens penetrate the skin in suscepible individuals. Requires prior contact and sensitization to the material eliciting the dermatitis.
Diagnosis
Subscribe To View
This article is available to subscribers.
Try a free trial today or contact us for more information.
Treatment
Subscribe To View
This article is available to subscribers.
Try a free trial today or contact us for more information.
Prevention
Subscribe To View
This article is available to subscribers.
Try a free trial today or contact us for more information.
Outcomes
Subscribe To View
This article is available to subscribers.
Try a free trial today or contact us for more information.
Further Reading
Publications
Refereed Papers
- Recent references from PubMed and VetMedResource.
Other sources of information
- Scott D W (1988) Large Animal Dermatology. W B Saunders, USA.
- Smith B P. Large Animal Internal Medicine. 5th edn. Elsevier.