Discussion
Infective endocarditis is not a disease of high incidence, but when it occurs, it can lead to several complications and even death, requiring prompt diagnosis and appropriate treatment.
In recent years, infective endocarditis associated with atopic dermatitis has been reported. Nakatani et al. reported that of 513 cases of infective endocarditis, 322 had some background factors, including atopic dermatitis in 5 cases.3 Fukunaga et al. reported 120 cases of infective endocarditis, of which, 8 were associated with atopic dermatitis (6.7%).4 In atopic dermatitis, the production of IL-4, IL-10, IL-13, etc. is high, suppressing the production of antibacterial peptides such as β-defensin and cathelicidin, which are related to skin defense,1and therefore rendering the skin susceptible to infection withStaphylococcus aureus . Consequently, Staphylococcus aureusis detected in more than 90% of patients with atopic dermatitis.2 Skin breakage due to scratching may allow bacterial invasion, resulting in bacteremia and infective endocarditis.
Infective endocarditis with a background of atopic dermatitis is common in young patients, and the most common causative organism is MSSA. It is also characterized by a high rate of embolism.5 These findings were observed in the present case.
Although there have been reports of cases of infective endocarditis caused by atopic dermatitis that did not require surgery and were relieved by antibiotics,6 and there is a report of a patient who used dupilumab to improve atopic dermatitis and then underwent standby surgery with good results,7 because cerebral infarction due to infective endocarditis is fatal, early surgical intervention is necessary when there is a high likelihood of recurrent embolization due to verrucous disease. Some reports suggest that early surgery for infective endocarditis is associated with early death, recurrent infective endocarditis, and valve dysfunction8; contrarily, other reports suggest that early surgery is useful for large verrucae.9 Infective endocarditis, especially when associated with atopic dermatitis, has been reported to have a high rate of embolism, and early surgery should always be kept in mind. Even right-sided infective endocarditis, which is considered sensitive to antibiotic therapy, may cause embolization or exacerbation of sepsis during treatment if atopic dermatitis is present in the background.10,11 In the present case, the patient had a mobile 10-mm verruca with a high likelihood of repeated embolization, prompting the policy of urgent surgery.
Additionally, the most common approach for surgical treatment of infective endocarditis is median sternotomy; however, there is a high possibility of postoperative mediastinitis with a median sternotomy, and some reports recommend a right thoracotomy.12 Although reliable verrucous resection and treatment of valvular disease are the highest priorities, a right small thoracotomy should be considered. In our case, we performed MICS and were able to avoid mediastinitis; the patient improved without wound infection.
Vancomycin and ceftriaxone were used for postoperative antibiotic therapy. The antibacterial activity of vancomycin and ceftriaxone against Staphylococcus aureus has been reported to be inferior to cefazolin13; however, given the multiple cerebral emboli, we chose ceftriaxone due to its good cerebrospinal fluid transfer.14 Close observation and skin treatment should be continued; moreover, the patient should be treated for atopic dermatitis in collaboration with a dermatologist.