Felis ISSN 2398-2950

Eosinophilic granuloma complex

Synonym(s): EGC, Eosinophilic skin disease, indolent ulcer, eosinophilic ulcer, rodent ulcer, eosinophilic plaque, collagenolytic granuloma, eosinophilic granuloma, linear granuloma

Contributor(s): Rosanna Marsella, David Scarff, David Godfrey


  • A term used to describe three different types of cutaneous reaction patterns with similar etiology, diagnosis and management.
  • Cause: various, most commonly hypersensitivity (particularly flea bite hypersensitivity).
  • Signs: indolent ulcer (ulcerated lesion on the upper lip), eosinophilic plaque (erythematous, raised, exudative lesions anywhere on the skin), collagenolytic granuloma (linear or nodular lesions anywhere on the skin or in the oral cavity).
  • Diagnosis: history, clinical signs, histopathology, trial treatments for the underlying cause.
  • Treatment: identification and correction of underlying cause or long-term symptomatic treatment if unable to identify underlying cause.
  • Prognosis: excellent provided underlying cause identified and treated, guarded otherwise.
    Print off the owner factsheet Feline eosinophilic granuloma complex Feline eosinophilic granuloma complex to give to your client.






Other causes

  • Genetic factors.


  • Eosinophilic plaques and collagenolytic granuloma: hypersensitivity thought to be causative in most cases.
  • Indolent ulcers Indolent ulcer: cause unclear? hypersensitivity thought to be involved.
  • Why an individual cat with a hypersensitivity develops a particular manifestation of EGC is unknown.
Eosinophilic plaque and collagenolytic granuloma
  • Inflammation (typically hypersensitivity or ectoparasites)   →   cellular infiltration by mast cells and eosinophils.
  • Mast cell degranulation   →   release of eosinophil chemotactic substances.
  • Eosinophilic granules   →   down regulation of inflammation, parasite destruction and collagenolysis.

Indolent ulcer

  • Unknown.


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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Wildermuth B E, Griffin C E & Rosenkrantz W S (2012) Response of feline eosinophilic plaques and lip ulcers to amoxicillin trihydreate-clavulanate potassium therapy: a randomized, double-blind placebo-controlled propspective study. Veterinary Dermatology 23 (2), 110-8 PubMed.
  • Persico P, Roccabianca P, Corona A et al (2011) Detection of feline herpes virus 1 via PCR and immunohistochemistry in cats with ulcerative facial dermatitis, eosinophilic granuloma complex reaction pattern and mosquito bite hypersensitivity. Veterinary Dermatology 22 (6), 521-527 PubMed.
  • Lee M, Bosward K L, Norris J M (2010) Immunohistolical evaluation of feline herpes-1 infection in feline eosinophilic dermatoses or stomatitis. Journal of Feline Medicine and Surgery 12 (2), 72-79 PubMed.
  • Leistra W H, Van Oost B A & Willemse T (2005) Non-pruritic granuloma in Norwegian Forrest cats. Veterinary Record 156 (18), 575-577 PubMed.
  • Bardag√≠ M, Fondati A, Fondevila D et al (2003) Ultrastructural study of cutaneous lesions in feline eosinophilic granuloma complex. Veterinary Dermatology 14 (6), 297-303 PubMed.
  • Columbini S, Hodgin E C, Foil C S et al (2001) Induction of feline flea allergy dermatitis and the incidence and histopathological characteristics of concurrent indolent lip ulcers. Veterinary Dermatology 12 (3), 155-161 PubMed.
  • Fondati A, Fondevila D & Ferrer L (2001) Histopathological study of feline eosinophilic dermatoses. Veterinary Dermatology 12 (6), 333-338 PubMed.
  • Mason K V & Evans A G (1991) Mosquito bite-caused eosinophilic dermatitis in cats. Journal of the American Veterinary Medical Association 198 (12), 2086-2088 PubMed.
  • Pentlarge V (1991) Eosinophilic conjunctivitis in five cats. Journal of the American Animal Hospital Association 27 (1), 21-28 PubMed.
  • Gelberg H B, Lewis R M, Felsburg P J et al (1985) Antiepithelial autoantibodies associated with the feline eosinophilic granuloma complex. Am J Vet Res 46 (1), 263-265 PubMed.
  • Langford L W, Selby L A (1979) Feline eosinophilic granuloma complex - a clinicoepidemiologic study of 32 cases. Vet Med Small Anim Clin 74 (5), 665-667 PubMed.

Other sources of information

  • Miller W H, Griffin C E & Campbell K L (2013) Feline eosinophilic granuloma complex. In: Muller and Kirk’s Small Animal Dermatology. Eds: Miller W H, Griffin C E & Campbell K L. Elsevier Mosby, St Louis Missouri pp 714.
  • Gross T et al (2005) Ulcerative and crusting dermatoses of the epidermis. In: Skin Diseases of the Dog and Cat, Clinical and Histopathologic Diagnosis. Ames Blackwell Science pp 116
  • Gross T et al (2005) Nodular and diffuse diseases of the dermis with prominent eosinophils, neutrophils or plasma cells. In: Skin Diseases of the Dog and Cat, Clinical and Histopathologic Diagnosis. Ames Blackwell Science pp 342.
  • Rosenkrantz W S (1992) Feline eosinophilic granuloma complex. In: Current Veterinary Dermatology the science and art of therapy. Eds: Griffin C E, Kwochka K W, MacDonald J M. Mosby Year Book, St Louis pp 319.
  • Power H (1990) Eosinophilic granuloma in a family of specific pathogen-free cats. In: Proceedings of the Annual Members Meeting of the American Academy of Veterinary Dermatology and American College of Veterinary Dermatology.