To The Editor: Infections are frequent in Sézary syndrome patients (SS) and are potentially life-threatening,1Blaizot R. Ouattara E. Fauconneau A. Beylot-Barry M. Pham-Ledard A. Infectious events and associated risk factors in mycosis fungoides/Sézary syndrome: a retrospective cohort study.Br J Dermatol. 2018; 179: 1322-1328Crossref PubMed Scopus (20) Google Scholar,2Scarisbrick J.J. Infections in mycosis fungoides and Sézary syndrome are a frequent cause of morbidity and contribute to mortality. What can be done?.Br J Dermatol. 2018; 179: 1243-1244Crossref PubMed Scopus (8) Google Scholar and the use of immunosuppressing agents contributes to their onset.3Posner L.E. Fossieck Jr., B.E. Eddy J.L. Bunn Jr., P.A. Septicaemic complications of the cutaneous T-cell lymphomas.Am J Med. 1981; 71: 210-216Abstract Full Text PDF PubMed Scopus (56) Google Scholar Herein, we report the infection rate, microbiological agents, and principal risk factors for infections in 113 SS patients (62 men, 54%) admitted to our clinic from 1976 to 2018. The mean age at the time of SS diagnosis was 69 years (range: 57-81 years). Twenty-seven patients (24%) had a history of mycosis fungoides before the diagnosis of SS. The mean number of circulating Sézary cells at the time of diagnosis was 6197/mm3 (1051-50,730 cells/mm3). Patients with a history of mycosis fungoides had a lower number of Sézary cells at the time of SS diagnosis (2988 cells/mm3) than those with a Sézary d'emblée (7204 cells/mm3). One hundred seven patients (95%) received active therapies (Supplementary Fig 1, available via Mendeley at https://doi.org/10.17632/cyj9b723c2.2). The most common treatment was chemotherapy, prescribed to 66 patients (58%), while 44 (39%) received targeted therapy, ie, alemtuzumab. During follow up, 77 patients (68%) presented with at least 1 infection (Tables I and II) (206 infectious episodes overall). Of these, 37 (48%) presented with a bacterial skin infection, 28 (36%) with a viral cutaneous infection, and 12 (16%) with fungal skin infections. The skin was the only site of infection in 30 patients (39%); 1 extracutaneous infection developed exclusively in 16 patients (21%), while 31 (40%) had both skin and extracutaneous involvement. Fourteen patients (18%) had sepsis preceded by 1 or more bacterial skin infections. Among the pathogens detected, viruses were the most frequent, and the most common site of infection was the skin. Eleven of the 77 infected patients (14.2%) presented with a cytomegalovirus (CMV) infection (recurrent in 2 cases), and all CMV infections developed in subjects treated with alemtuzumab. Staphylococcus aureus was the main pathogen detected in bacterial bloodstream infections (n = 17, 61%), of which 6 (35%) were methicillin-resistant.Table IInfection typologyInfectious agentsGroupsClinical manifestationsMicrobiological classificationPathogen isolated (I) or suspected (S)No. of casesBacterialSkin and soft-tissue infectionsImpetigoGram-positiveStaphylococcus spp.11Streptococcus spp.8CellulitisGram-positiveStaphylococcus spp.4Gram-negativeMorganella spp.2Enterobacter spp.1Pseudomonas spp.1Proteus spp.1Stenotrophomonas spp.1AnaerobesBacteroides spp.1Bloodstream infectionBloodstream infectionsGram-positiveMSSA11MRSA6CoNS3Streptococcus spp.4Gram-negativePseudomonas spp.2Klebsiella spp.1E.coli1Lower respiratory tract infectionPneumoniaGram-positiveMRSA2Urinary tract infectionLower urinary tract infectionGram-positiveMSSA1Gram-negativeE.coli364CoNS, Coagulase negative Staphylococci; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-sensitive Staphylococcus aureus. Open table in a new tab Table IIInfection typology- section IIInfectious agentsGroupsClinical manifestationsPathogen isolated (I) or suspected (S)No. of casesViralSkin and soft-tissue infectionsSuperficial skin infectionsHSV33VZV10Poxvirus1Bloodstream infectionBloodstream infectionsCMV11EBV1Parvovirus1Lower respiratory tract infectionPneumoniaCMV2Head, ear, eye, nose, and throat infectionsKerato-conjunctivitisHSV1Liver infectionsHepatitisHBV3HCV1Gastrointestinal infectionsGastroenteritisNorovirus165FungalSkin and soft-tissue infectionsSuperficial skin infectionsCandida spp.5Scopulariopsis spp.1Mucosal infectionsCandida spp.7Lower respiratory tract infectionPneumoniaPneumocystis carinii1Aspergillus spp.2Head, ear, eye, nose, and throat infectionsOtitisAspergillus spp.1Candida spp.118ParasitesLiver infectionsCystic lesionsEchinococcus spp.1UnknownSkin and soft-tissue infectionsTinea corporis1Tinea pedis1Impetigo3Erysipelas1Surgical wound1Skin abscess2Head, ear, eye, nose, and throat infectionsOtitis5Dental abscess1Keratitis2Lower respiratory tract infectionPneumonia28Bacterial joint infectionAbscess of the rachis1Osteomyelitis1Spondylodiscitis158CMV, Cytomegalovirus; EBV, Epstein-Barr virus; HBV, hepatitis B virus; HCV, hepatitis C virus; HSV, herpes simplex virus; VZV, varicella zoster virus. Open table in a new tab CoNS, Coagulase negative Staphylococci; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-sensitive Staphylococcus aureus. CMV, Cytomegalovirus; EBV, Epstein-Barr virus; HBV, hepatitis B virus; HCV, hepatitis C virus; HSV, herpes simplex virus; VZV, varicella zoster virus. Previous treatment with chemotherapy and/or alemtuzumab was associated with a significantly increased risk of at least 1 infection (50% vs 74%, respectively; P = .02). Among patients who underwent chemotherapy and alemtuzumab, an infection developed in 25 (86%), while among patients who received chemotherapy alone, an infectious event developed in 31 (66%). One hundred two patients (90.3%) died after a median follow up of 1.85 years (0.05-10.67 years) from the time of SS diagnosis. Among 66 deceased patients in whom infections had developed, 27 (41%) died because of infection-related complications; in this subgroup, 18 patients (66.6%) died because of bacterial sepsis, while 6 (22%) presented with both bacterial sepsis and CMV infection before they died. Infections developed in 77 patients (68%) in our SS cohort, which is a higher percentage than that reported in the literature.4Axelrod P.I. Lorber B. Vonderheid E.C. Infections complicating mycosis fungoides and Sézary syndrome.JAMA. 1992; 267: 1354-1358Crossref PubMed Scopus (178) Google Scholar Despite the predominance of bacterial skin infections reported in the literature,1Blaizot R. Ouattara E. Fauconneau A. Beylot-Barry M. Pham-Ledard A. Infectious events and associated risk factors in mycosis fungoides/Sézary syndrome: a retrospective cohort study.Br J Dermatol. 2018; 179: 1322-1328Crossref PubMed Scopus (20) Google Scholar,2Scarisbrick J.J. Infections in mycosis fungoides and Sézary syndrome are a frequent cause of morbidity and contribute to mortality. What can be done?.Br J Dermatol. 2018; 179: 1243-1244Crossref PubMed Scopus (8) Google Scholar we observed a higher incidence of viral skin infections (n = 44, 21%; of these, 28 patients experienced a recurrent infection). The frequency of CMV infections in alemtuzumab-treated patients with cutaneous T-cell lymphoma has been reported to be between 10% and 18%.5Thursky K.A. Worth L.J. Seymour J.F. Miles Prince H. Slavin M.A. Spectrum of infection, risk and recommendations for prophylaxis and screening among patients with lymphoproliferative disorders treated with alemtuzumab.Br J Haematol. 2006; 132: 3-12Crossref PubMed Scopus (158) Google Scholar Our cohort showed a similar percentage, but in this case cohort, patients were diagnosed with SS. In conclusion, SS patients are at a particular risk of sepsis and subsequent death secondary to bacterial and viral infections. Cutaneous herpes simplex infections, S aureus skin infections, and CMV infections were predominant in our alemtuzumab- and/or chemotherapy-treated patients. None disclosed. The authors thank Prof Emeritus Maria Grazia Bernengo, MD, Former Director of the Dermato-Oncology Department at the University of Turin, who started the prospective collection of SS patients in our unit more than 30 years ago, all of whom are very grateful for her tuition and support. The authors also thank Laurene Kelly for language revision.