Capabilities of optical coherence tomography (OCT) as well as OCT enhanced by tissue clearing using glycerol solution for differential diagnosis of erythematoses, bullous and papulous skin diseases are demonstrated on 118 patients sample. It is shown that high-skilled dermatologists familiar with fundamentals of skin pathomorphology but without previous experience in OCT studies and interpretation of optical features are capable, when using OCT, of distinguishing optical images of various skin diseases to a high diagnostic accuracy (ranging from 76% to 94%) and with good multirater interobserver agreement between different specialists (kappa up to 0.69). Application of glycerol improves contrast and penetration depth of OCT images of skin significantly, thus reliably improving diagnostic validity of the technique and facilitating differential diagnosis of clinically similar dermatoses accompanied by papulous eruption.