Editing Cellulitis (section)

===Differential diagnosis===
Other conditions that may mimic cellulitis include [[Venous thrombosis|deep vein thrombosis]], which can be diagnosed with a compression leg [[medical ultrasonography|ultrasound]], and [[stasis dermatitis]], which is inflammation of the skin from poor blood flow. Signs of a more severe infection such as necrotizing fasciitis or [[gas gangrene]] that would require prompt surgical intervention include purple [[bulla (dermatology)|bulla]]e, skin sloughing, subcutaneous edema, and systemic toxicity.<ref name=":0" /> Misdiagnosis can occur in up to 30% of people with suspected lower-extremity cellulitis, leading to 50,000 to 130,000 unnecessary hospitalizations and $195 to $515 million in avoidable healthcare spending annually in the United States.<ref>{{Cite journal |last1=Weng |first1=Qing Yu |last2=Raff |first2=Adam B. |last3=Cohen |first3=Jeffrey M. |last4=Gunasekera |first4=Nicole |last5=Okhovat |first5=Jean-Phillip |last6=Vedak |first6=Priyanka |last7=Joyce |first7=Cara |last8=Kroshinsky |first8=Daniela |last9=Mostaghimi |first9=Arash |title=Costs and Consequences Associated With Misdiagnosed Lower Extremity Cellulitis |journal=JAMA Dermatology |volume=153 |issue=2 |pages=141–146 |doi=10.1001/jamadermatol.2016.3816 |pmid=27806170 |year=2017 |s2cid=205110504 |url=https://dash.harvard.edu/bitstream/1/33785925/1/jamadermatology_Weng_2016_oi_160057.pdf }}</ref> Evaluation by dermatologists for cases of suspected cellulitis has been shown to reduce misdiagnosis rates and improve patient outcomes.<ref name="pmid29453874">{{cite journal |vauthors = Li DG, Xia FD, Khosravi H, Dewan AK, Pallin DJ, Baugh CW | display-authors=etal |title=Outcomes of Early Dermatology Consultation for Inpatients Diagnosed With Cellulitis. |journal=JAMA Dermatol |year=2018 |volume=154 |issue=5 |pages=537–543 |pmid=29453874 |doi=10.1001/jamadermatol.2017.6197 |pmc=5876861}}</ref><ref name="pmid29453872">{{cite journal |vauthors = Ko LN, Garza-Mayers AC, St John J, Strazzula L, Vedak P, Shah R | display-authors=etal |title=Effect of Dermatology Consultation on Outcomes for Patients With Presumed Cellulitis: A Randomized Clinical Trial. |journal=JAMA Dermatol |year=2018 |volume=154 |issue=5 |pages=529–536 |pmid=29453872 |doi=10.1001/jamadermatol.2017.6196 |pmc=5876891}}</ref>

Associated musculoskeletal findings are sometimes reported. When it occurs with [[acne conglobata]], [[hidradenitis suppurativa]], and [[pilonidal cyst]]s, the syndrome is referred to as the [[follicular occlusion triad]] or tetrad.<ref>{{cite journal |vauthors=Scheinfeld NS |title=A case of dissecting cellulitis and a review of the literature |journal=Dermatology Online Journal |volume=9 |issue=1 |pages=8 |date=February 2003 |doi=10.5070/D39D26366C |pmid=12639466 }}</ref>

[[Lyme disease]] can be misdiagnosed as cellulitis. The characteristic [[Erythema chronicum migrans|bullseye rash]] does not always appear in Lyme disease (the rash may not have a central or ring-like clearing, or not appear at all).<ref name=wright_2012>{{cite journal |last1=Wright |first1=William F. |last2=Riedel |first2=David J. |last3=Talwani |first3=Rohit |last4=Gilliam |first4=Bruce L. |title=Diagnosis and management of Lyme disease |journal=American Family Physician |date=1 June 2012 |volume=85 |issue=11 |pages=1086–1093 |pmid=22962880 |url=https://www.aafp.org/link_out?pmid=22962880 }}</ref> Factors supportive of Lyme include recent outdoor activities where Lyme is common and rash at an unusual site for cellulitis, such as [[armpit]], [[groin]], or behind the knee.<ref name=CDC-Lyme-Data>{{cite web |title=Lyme Disease Data and surveillance |url=https://www.cdc.gov/lyme/datasurveillance/ |website=Lyme Disease |publisher=Centers for Disease Control and Prevention |access-date=April 12, 2019 |date=2019-02-05 |archive-date=2019-04-13 |archive-url=https://web.archive.org/web/20190413133319/https://www.cdc.gov/lyme/datasurveillance/ |url-status=live }}</ref><ref name=wright_2012/> Lyme can also result in long-term neurologic complications.<ref name=Aucott2015>{{cite journal |vauthors=Aucott JN |title=Posttreatment Lyme disease syndrome |journal=Infectious Disease Clinics of North America |volume=29 |issue=2 |pages=309–323 |date=June 2015 |pmid=25999226 |doi=10.1016/j.idc.2015.02.012}}</ref> The standard treatment for cellulitis, [[cephalexin]], is not useful in Lyme disease.<ref name=IDSALyme2006/> When it is unclear which one is present, the [[Infectious Diseases Society of America|IDSA]] recommends treatment with [[cefuroxime axetil]] or [[amoxicillin/clavulanic acid]], as these are effective against both infections.<ref name=IDSALyme2006/>