These findings suggest that teledermatology can be used by attending dermatologists to confidently and accurately diagnose both cases of cellulitis and pseudocellulitis, corroborating previous findings [17, 18]. Our results expand existing knowledge by demonstrating that augmented teledermatology with additional data from a standardized cellulitis questionnaire and thermal imaging can further improve diagnostic accuracy for cellulitis specifically, while pseudocellulitis diagnostic accuracy remained ≥ 94% regardless of amount of clinical data. Decisions considered essential to patient safety (i.e. continuing antibiotics for cases of true cellulitis) were consistently appropriate, and these, as well as all other management decisions, remained largely stable despite access to increasing amounts of patient data.
These results contribute to growing data related to not only the utility of teledermatology, but also the structure of teledermatology. Augmented teledermatology with standardized questionnaires19 and additional technology [20] has been studied in the setting of cutaneous oncology, but not for presumed cellulitis [17, 18]. We found that augmentation of standard store-and-forward teledermatology, with the addition of a standardized cellulitis questionnaire and thermal imaging, may improve accuracy for cases of cellulitis (OR: 2.35, 95% CI: 1.19–4.65), and that this increased accuracy will benefit patients who can’t receive in-person dermatology consultation (NNT = 5.7 (95% CI 3.4–14.9).
While the cellulitis questionnaire is free and easy to interpret by any admitting clinician, thermal imaging requires monetary investment, effort, and training on the part of the primary treatment team. Furthermore, we provided thermal image data to teledermatologists without specific training, and in our study, it was unknown what level of experience, if any, participating dermatologists had in interpreting thermal images. The overall cost-benefit ratio of thermal imaging must therefore be evaluated further, as well as comparing the impact it has on diagnosis between dermatologists with and without previous experience in interpreting thermal imaging data.
Attending dermatologists were able to accurately diagnose regardless of their experience with inpatient dermatology consultations, reducing concerns that accuracy via teledermatology would be limited to attendings with extensive experience with inpatient cellulitis diagnosis [17]. This finding increases the pool of dermatologists who could potentially aid in the management of presumed cellulitis at smaller, non-academic hospitals that often lack inpatient consult services and disproportionately admit patients presenting with skin disease [15, 25].
Decisions around laboratory testing remained largely stable for cases of cellulitis and pseudocellulitis despite increasing amounts of clinical information. Importantly, the decision to continue antibiotics for cases of true cellulitis consistently remained above 95%, higher than the percentage of dermatologists who accurately diagnosed those cases as cellulitis. Paradoxically, the recommendation to discontinue antibiotics for cases of pseudocellulitis decreased from 93% with initial H&P to 86% with the addition of standardized questions and thermal images. While still consistent with previously reported data on antibiotic discontinuation for cases of pseudocellulitis diagnosed via teledermatology (87%) [18], this finding suggests worsening antibiotic stewardship in scenarios with greater information transfer.
Decisions regarding admission or discharge are difficult to interpret, as there are no consensus guidelines. Factors external to what was presented in our cases may guide clinical choices and the data presented in these cases was not sufficiently comprehensive to include all factors that a physician may consider when making admission decisions. That said, the decision to recommend discharge for cases of pseudocellulitis was consistently ≥ 95% among our cohort of teledermatologists, similar to previous findings among patients that received in-person dermatology consultation [4]. For cellulitis, fewer of our study’s teledermatologists recommended admission compared to dermatologists who consulted in-person [5]. This may be related to this study’s inability to recreate the same risk threshold dermatologists would encounter when making real-time decisions for patients directly under their care. Future studies should analyze trends in admission recommendations for cases of true cellulitis that received teledermatology as the primary dermatology consultation.
The disconnect between improving diagnostic accuracy and confidence with additional patient information and a lack of change in testing and evaluation suggests that the latter may be a function of intrinsic clinician preference and practice habits. Standardizing approaches and reducing unnecessary testing may be better addressed by point-of-care decision support that helps physicians link the utility of their requested tests in the specific clinical scenario they are evaluating.
Our findings regarding diagnostic accuracy and antibiotic stewardship with augmented teledermatology are similar to previous studies investigating in-person dermatology consultation [4, 8]. These improved management decisions, when considered along with the incidence of cellulitis and the cost of US hospital admissions, has the potential for significant economic and patient safety outcomes [10]. These findings are reinforced in the context of the current COVID-19 pandemic, during which teledermatology has been expanded to limit the number of person-to-person contacts and decrease personal protective equipment use [26].
These results must be considered within the context of our study design. The official diagnosis for each case was determined by in-person dermatology consultation, and while each case had 30 days of follow-up, the diagnosis may not represent the true diagnosis. Although all survey cases were real clinical cases presenting to the ED, the attendings who took our survey were not actively treating these patients, and their risk threshold and decision making may change in real life settings. All survey cases initially presented to the emergency department of a single academic institution, a setting for which improved diagnostic accuracy would be useful given the high incidence of cellulitis presenting to the ED [1]. All respondents were members of academic departments, and future studies should include dermatologists practicing in additional settings.