Agent Orange Exposure Fairness Act of 2018 This bill, with respect to veterans exposed to certain herbicide agents during military, naval, or air service in Vietnam between January 9, 1962, and May 7, 1975: (1) removes the manifestation period required for presumption of service connection for chloracne and porphyria cutanea tarda, and (2) includes in such presumption acute and subacute peripheral neuropathy becoming manifest to a disability degree of 10% or more. Under a presumption of service-connection, specific disabilities diagnosed in certain veterans are presumed to have been caused by the circumstances of their military service. Health care benefits and disability compensation may then be awarded without having to go through a separate adjudicative process.