Recently, there has been great progress in the ability of artificial intelligence (AI) algorithms to classify dermatological conditions from clinical photographs. However, little is known about the robustness of these algorithms in real-world settings where several factors can lead to a loss of generalizability. Understanding and overcoming these limitations will permit the development of generalizable AI that can aid in the diagnosis of skin conditions across a variety of clinical settings. In this retrospective study, we demonstrate that differences in skin condition distribution, rather than in demographics or image capture mode are the main source of errors when an AI algorithm is evaluated on data from a previously unseen source. We demonstrate a series of steps to close this generalization gap, requiring progressively more information about the new source, ranging from the condition distribution to training data enriched for data less frequently seen during training. Our results also suggest comparable performance from end-to-end fine tuning versus fine tuning solely the classification layer on top of a frozen embedding model. Our approach can inform the adaptation of AI algorithms to new settings, based on the information and resources available.

Domain adaptation which pays attention to exploiting the knowledge in source domain to promote the learning tasks in target domain plays a critical role in real-world applications. Recently, lots of deep learning approaches based on autoencoders have achieved significance performance in domain adaptation. However, most existing methods focus on minimizing the distribution divergence by putting the source data and target data together to learn global feature representations, while do not take the local relationship between instances of the same category in different domains into account. To address this problem, we propose a novel Semi-Supervised Representation Learning framework via Dual Autoencoders for domain adaptation, named SSRLDA. More specifically, \textcolor{red}{we extract richer feature representations by learning the global and local feature representations simultaneously using two novel autoencoders}, which are referred to as marginalized denoising autoencoder with adaptation distribution (MDA$_{ad}$) and multi-class marginalized denoising autoencoder (MMDA) respectively. Meanwhile, we \textcolor{red}{adopt an iterative strategy} to make full use of label information to optimize feature representations. Experimental results show that our proposed approach outperforms several state-of-the-art baseline methods.