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BACKGROUND Cladosporium and Corynespora cassiicola ( C. cassiicola ) infections rarely occur in humans. Mutations in human caspase recruitment domain protein 9 (CARD9) are reported to be associated with fungal diseases. Pulmonary Cladosporium infection coexisting with subcutaneous C. cassiicola infection in a patient with a CARD9 mutation has not been reported in the literature. CASE SUMMARY A 68-year-old male patient was hospitalized for hypertrophic erythema and deep ulcers on the left upper extremity. He was diagnosed with pneumonia caused by Cladosporium , as identified through bronchoalveolar lavage fluid analysis, and deep dermatophytosis caused by C. cassiicola , as identified through morphological characteristics of the wound secretion culture. He underwent antifungal therapy (voriconazole) and recovered successfully. He carried two mutations in CARD9 (chr9:139266425 and chr9:139262240) and was therefore susceptible to fungal infections. CONCLUSION This case study is the first to report the coexistence of pulmonary Cladosporium infection and subcutaneous C. cassiicola infection in a patient with CARD9 mutation. Our findings will be helpful in enriching the phenotypic spectrum of fungal infections underlying CARD9 deficiency.

Rationale:Behcet disease(BD) and Sjogren syndrome(SS) are separate conditions that rarely concomitantly affect an individual. In theory,mild symptoms of patients with BD or SS are easy to igore and,thus,remain undiagnosed. There,it is reasonable to believe there may be some clinical cases of combined diseases that go undiscovered and which needs to be taken seriously. In addition,it has been suggested that herpes simplex virus(HSV) types 1 and 2 are associated with BD,but have not been shown to be correlated to the direct pathogenesis of BD. The role of HSV in BD needs more research and attention.Patient concerns:Here,we report a young woman who had both BD and SS. The first symptom of the disease was fever. However,the HSV type 1 IgG and HSV type 2 IgM antibody results were positive in our case and,which rendered this case unique.Diagnoses:BD and SS concomitantly affect the individual,and BD was the acute type.Interventions:IV methylprednisolone was used for 9 days and then oral glucocorticoids was used to instead,and the treatment works very well.Outcomes: BD and SS can concomitantly affect an individual,and we believe that HSV-2 may be directly related to the pathogenesis of BD. The nature of BD as an auto-inflammatory disorder, autoimmune disorder, or both, is controversial. If we can find more patients who combined affected these two disease, it might helpful for us to understand the nature of BD.Lessons:For patients with clinical diagnosis of BD or SS,we need to be alert that it may combinded the other disease. Long term follow up and detailed inspection are important means to avoid undiscovered.