A celulite se desenvolve quando microrganismos entram na derme e nos tecidos subcutâneos através de rupturas na barreira cutânea. Os estreptococos beta-hemolíticos e o Staphylococcus aureus são os agentes causadores da celulite mais comumente implicados.[6]Sigurdsson AF, Gudmundsson S. The etiology of bacterial cellulitis as determined by fine-needle aspiration. Scand J Infect Dis. 1989;21(5):537-42.
http://www.ncbi.nlm.nih.gov/pubmed/2587954?tool=bestpractice.com
[7]Bernard P, Bedane C, Mounier M, et al. Streptococcal cause of erysipelas and cellulitis in adults. A microbiologic study using a direct immunofluorescence technique. Arch Dermatol. 1989 Jun;125(6):779-82.
http://www.ncbi.nlm.nih.gov/pubmed/2658843?tool=bestpractice.com
[8]Eriksson B, Jorup-Ronstrom C, Karkkonen K, et al. Erysipelas: clinical and bacteriologic spectrum and serological aspects. Clin Infect Dis. 1996 Nov;23(5):1091-8.
http://www.ncbi.nlm.nih.gov/pubmed/8922808?tool=bestpractice.com
[9]Gunderson CG, Martinello RA. A systematic review of bacteremias in cellulitis and erysipelas. J Infect. 2012 Feb;64(2):148-55.
http://www.ncbi.nlm.nih.gov/pubmed/22101078?tool=bestpractice.com
[10]Chira S, Miller LG. Staphylococcus aureus is the most common identified cause of cellulitis: a systematic review. Epidemiol Infect. 2010 Mar;138(3):313-7.
http://www.ncbi.nlm.nih.gov/pubmed/19646308?tool=bestpractice.com
[11]Sartelli M, Coccolini F, Kluger Y, et al. WSES/GAIS/WSIS/SIS-E/AAST global clinical pathways for patients with skin and soft tissue infections. World J Emerg Surg. 2022 Jan 15;17(1):3.
https://wjes.biomedcentral.com/articles/10.1186/s13017-022-00406-2
http://www.ncbi.nlm.nih.gov/pubmed/35033131?tool=bestpractice.com
No entanto, outros microrganismos podem raramente resultar em celulite. Geralmente, ocorre em um hospedeiro com imunidade alterada ou em consequência de uma exposição específica (por exemplo, ambiente aquático ou mordida de animal ou ser humano).[12]Raff AB, Kroshinsky D. Cellulitis: a review. JAMA. 2016 Jul 19;316(3):325-37.
http://www.ncbi.nlm.nih.gov/pubmed/27434444?tool=bestpractice.com
Esses organismos incluem Pseudomonas aeruginosa, Pasteurella multocida, Capnocytophaga canimorsus, Vibrio vulnificus e Cryptococcus neoformans.[12]Raff AB, Kroshinsky D. Cellulitis: a review. JAMA. 2016 Jul 19;316(3):325-37.
http://www.ncbi.nlm.nih.gov/pubmed/27434444?tool=bestpractice.com
[13]Gunderson CG. Cellulitis: definition, etiology, and clinical features. Am J Med. 2011 Dec;124(12):1113-22.
http://www.ncbi.nlm.nih.gov/pubmed/22014791?tool=bestpractice.com
[14]Dalal A, Eskin-Schwartz M, Mimouni D, et al. Interventions for the prevention of recurrent erysipelas and cellulitis. Cochrane Database Syst Rev. 2017 Jun 20;6(6):CD009758.
https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD009758.pub2/full
http://www.ncbi.nlm.nih.gov/pubmed/28631307?tool=bestpractice.com
A celulite não purulenta é mais comumente causada por estreptococos beta-hemolíticos.[15]Jeng A, Beheshti M, Li J, et al. The role of beta-hemolytic streptococci in causing diffuse, nonculturable cellulitis: a prospective investigation. Medicine (Baltimore). 2010 Jul;89(4):217-26.
https://journals.lww.com/md-journal/fulltext/2010/07000/the_role_of___hemolytic_streptococci_in_causing.4.aspx
http://www.ncbi.nlm.nih.gov/pubmed/20616661?tool=bestpractice.com
A fisiopatologia da celulite não tem sido bem estudada. A carga de organismos na celulite parece ser baixa.[12]Raff AB, Kroshinsky D. Cellulitis: a review. JAMA. 2016 Jul 19;316(3):325-37.
http://www.ncbi.nlm.nih.gov/pubmed/27434444?tool=bestpractice.com
Alguns têm especulado que as exotoxinas pirogênicas produzidas pelos estreptococos beta-hemolíticos podem contribuir para os achados clínicos da celulite.[16]Ki V, Rotstein C. Bacterial skin and soft tissue infections in adults: a review of their epidemiology, pathogenesis, diagnosis, treatment and site of care. Can J Infect Dis Med Microbiol. 2008 Mar;19(2):173-84.
https://onlinelibrary.wiley.com/doi/10.1155/2008/846453
http://www.ncbi.nlm.nih.gov/pubmed/19352449?tool=bestpractice.com
Há evidências de produção local de citocinas inflamatórias pelos ceratinócitos.[17]Kupper TS. Immune and inflammatory processes in cutaneous tissues. Mechanisms and speculations. J Clin Invest. 1990 Dec;86(6):1783-9.
http://www.jci.org/articles/view/114907/pdf
http://www.ncbi.nlm.nih.gov/pubmed/2254445?tool=bestpractice.com
A interação entre as proteínas de superfície do Streptococcus pyogenes e as adesões na superfície dos ceratinócitos e das células de Langerhans pode ser necessária para que a infecção se desenvolva.[18]Okada N, Pentland AP, Falk P, et al. M Protein and protein F act as important determinants of cell-specific tropism of Streptococcus pyogenes in skin tissue. J Clin Invest. 1994 Sep;94(3):965-77.
http://www.jci.org/articles/view/117463
http://www.ncbi.nlm.nih.gov/pubmed/8083381?tool=bestpractice.com
Mecanismos comuns de ruptura da barreira cutânea incluem lacerações, feridas por mordida, instrumentação (por exemplo, agulhas), afecções de pele preexistentes e cirurgia.[16]Ki V, Rotstein C. Bacterial skin and soft tissue infections in adults: a review of their epidemiology, pathogenesis, diagnosis, treatment and site of care. Can J Infect Dis Med Microbiol. 2008 Mar;19(2):173-84.
https://onlinelibrary.wiley.com/doi/10.1155/2008/846453
http://www.ncbi.nlm.nih.gov/pubmed/19352449?tool=bestpractice.com
Em muitos casos, a tinha do pé pode causar um ruptura na barreira cutânea e permitir a entrada de organismos bacterianos desencadeantes.[19]Semel JD, Goldin H. Association of athlete's foot with cellulitis of the lower extremities: diagnostic value of bacterial cultures of ipsilateral interdigital space samples. Clin Infect Dis. 1996 Nov;23(5):1162-4.
http://www.ncbi.nlm.nih.gov/pubmed/8922818?tool=bestpractice.com