Background: Parkinson's disease (PD) and the skin are related in a number of ways, including clinical abnormalities of the disease itself and skin-related side effects of dopaminergic medication, pumps, and surgical therapies. Recent advances in understanding the role of a-synuclein suggest skin biopsies as a potential diagnostic or even a premotor marker of PD. Methods: The PubMed database was searched for publications up to October 2015, and the current evidence on skin-related issues in PD was comprehensively summarized. Results: The evidence was summarized on the prevalence, etiology, and management of seborrheic dermatitis, sweating dysfunctions, bullous pemphigoid, and malignant melanoma, as well as therapy-related skin disorders, especially those observed in amantadine, rotigotine, apomorphine, and levodopa/carbidopa intestinal gel therapies and deep-brain stimulation. Skin biopsies evaluating the presence of a-synuclein, the density and morphology of cutaneous nerves, and skin fibroblast functions also are discussed. Conclusions: Skin disorders are a common manifestation of PD. However, the exact pathophysiology and prevalence of these disorders are not well understood, and more systematic research is needed in this regard. Peripheral tissue biopsies as a diagnostic marker of PD are an exciting avenue in future PD research, although multiple caveats and pending issues need to be solved before they can be used in routine clinical practice.Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by the presence of multiple motor and nonmotor symptoms. Skin disorders, such as seborrheic dermatitis (SD) and hyperhidrosis, are well recognized and frequent -but often overlooked-nonmotor symptoms of PD; they have been associated with PD for nearly a century, since the first reports of seborrheic facies in PD by Krestin.1 Given the interest in biomarkers that precede the motor features of PD, it is worth noting that skin affection may precede the onset of typical motor symptoms by years. 2 Other skin disorders, such as malignant melanoma and bullous pemphigoid (BP), are significantly more prevalent in PD patients compared with the general population. 3,4 Recent advances in the understanding of the role of a-synuclein (SNCA) in the pathophysiology of PD, its prion-like mechanism of spreading, and findings of typical Lewy body pathology in the peripheral nervous system, suggest skin biopsies as a potential diagnostic marker of PD. Unlike the peripheral melanins produced in skin melanocytes, neuromelanin is produced in specific populations of catecholaminergic neurons in the brain. It is believed that neuromelanin interacts with transition metals, especially iron, and mediates intracellular oxidative mechanisms. This function seems to be compromised in PD, thus rendering pigmented neurons vulnerable to oxidative damage. 5 The skin can be affected by antiparkinsonian medication as well. Specific drug-delivery methods, such as skin patches, subcutaneous application of apomorphine, l...