Supplementary Table 1.

Excluded Studies With Reason For Exclusion

Authors	Title	Reason for Exclusion
Lee et al [1]	Correlations between histopathologic and dermoscopic findings in Korean actinic keratosis.	Correlation between histopathology and dermoscopy. Retrospective study of nonpigmented AKs; aimed to describe histopathological findings with dermoscopic ones. Description of dermoscopic features’ frequency.
Micantonio et al [2]	A new dermoscopic algorithm for the differential diagnosis of facial lentigo maligna and pigmented actinic keratosis.	Aimed to distinguish between PAK and LM. Dermoscopic patterns to distinguish PAK from LM.
Gómez-Martín et al [3]	Diagnostic accuracy of non-melanocytic pink flat skin lesions on the legs: Dermoscopic and reflectance confocal microscopy evaluation.	AK grouped with other skin lesions. Study included all pink lesions. The clinical suspicion is divided into 2 groups: malignant or benign, does not give data specifically of AK (AK grouped with inflammatory disease group).
Kelati et al [4]	Dermoscopy of pigmented actinic keratosis of the face: a study of 232 cases.	Does not follow diagnostic study design flow. Determines frequency of dermoscopic signs.
Lee et al [5]	Correlations between dermoscopic and histopathologic findings in actinic keratosis.	Poster. Article from this poster was published in 2019 1.
Li and Chang [6]	The investigation of dermoscopy in differential diagnosis of facial actinic keratosis.	Poster.
Lallas et al [7]	Dermoscopic clues to differentiate facial lentigo maligna from pigmented actinic keratosis.	Does not follow diagnostic study design flow. Aim of the study was to determine the frequency of the dermoscopic criteria for facial pigmented lesions.
Elwan et al [8]	Dermoscopic and histopathological correlation in some epidermal tumors: A preliminary study.	Does not follow diagnostic study design flow. The study aimed to study epidermal tumors (BCC, SK, AK, and SCC).
Tschandl et al [9]	Dermatoscopy of flat pigmented facial lesions.	AK grouped with other skin lesions. Considers PAK and pigmented Bowen’s disease as one group.
Rosendahl [10]	Diagnostic accuracy of dermatoscopy for melanocytic and nonmelanocytic pigmented lesions.	AK grouped with other skin lesions. Adequate study design and flow, however, it groups all skin lesions into 2 groups: malignant or benign. No specific data on AKs.
Akay et al [11]	Dermatoscopy of flat pigmented facial lesions: Diagnostic challenge between pigmented actinic keratosis and lentigo maligna.	Aimed to distinguish between PAK and LM. Lesions were included only if they presented with specific patterns of LM.
Cinotti et al [12]	Dermoscopy vs. reflectance confocal microscopy for the diagnosis of lentigo maligna.	Evaluation of different diagnostic tool. Diagnostic accuracy study of dermoscopy and RCM for the diagnosis of LM.
Wurm et al [13]	The value of reflectance confocal microscopy in diagnosis of flat pigmented facial lesions: a prospective study.	Evaluation of different diagnostic tool. Aim of the study was to describe utility of confocal microscopy on different flat, pigmented lesions.
Guitera et al [14]	Dermoscopy and in vivo confocal microscopy are complementary techniques for diagnosis of difficult amelanotic and light-coloured skin lesions.	Does not follow diagnostic study design flow. Study included different amelanotic and light-colored lesions. Aim was for diagnosis of melanoma.
Stoica et al [15]	Dermatoscopic and histopathological aspect of preneoplasia and skin cancers - study on 74 patients.	Correlation between histopathology and dermoscopy. Aimed to correlate the dermoscopic and histopathological aspect of tumors.

AK = Actinic keratosis; PAK = pigmented actinic keratosis; LM = lentigo maligna, RCM = reflectance confocal microscopy