It has moderate liability among addictive drugs; accordingly, addiction and psychological dependence are possible and likely when methylphenidate is used at high doses as a recreational drug. When used above the medical dose range, stimulants are associated with the development of stimulant psychosis. As with all addictive drugs, the overexpression of ΔFosB in D1-type medium spiny neurons in the nucleus accumbens is implicated in methylphenidate addiction. Biomolecular mechanisms
Methylphenidate has the potential to induce euphoria due to its pharmacodynamic effect (i.e., dopamine reuptake inhibition) in the brains reward system. At therapeutic doses, ADHD stimulants do not sufficiently activate the reward system, or the reward pathway in particular, to the extent necessary to cause persistent increases in ΔFosB gene expression in the D1-type medium spiny neurons of the nucleus accumbens; consequently, when taken as directed in doses that are commonly prescribed for the treatment of ADHD, methylphenidate use lacks the capacity to cause an addiction. However, when methylphenidate is used at sufficiently high recreational doses through a bioavailable route of administration (e.g., insufflation or intravenous administration), particularly for use of the drug as a euphoriant, ΔFosB accumulates in the nucleus accumbens. Hence, like any other addictive drug, regular recreational use of methylphenidate at high doses eventually gives rise to ΔFosB overexpression in D1-type neurons which subsequently triggers a series of gene transcription-mediated signaling cascades that induce an addiction. Interactions
Methylphenidate may inhibit the metabolism of vitamin K anticoagulants, certain anticonvulsants, and some antidepressants (tricyclic antidepressants, and selective serotonin reuptake inhibitors).
Feeding bites
Feeding bites have characteristic patterns and symptoms, a function of the feeding habits of the offending pest and the chemistry of its saliva. Microscopic appearance
The histomorphologic appearance of insect bites is usually characterized by a wedge-shaped superficial dermal perivascular infiltrate consisting of abundant lymphocytes and scattered eosinophils. This appearance is non-specific, i.e. it may be seen in a number of conditions including:
Drug reactions,
Urticarial reactions,
Prevesicular early stage of bullous pemphigoid, and
HIV related dermatoses. See also
List of biting or stinging arthropods
Spider bite
Insect bite relief stick
Schmidt sting pain index
Bee  sting
Allergy

References
External links

Venomous Arthropods chapter in United States Environmental Protection Agency and University of Florida/Institute of Food and Agricultural Sciences National Public Health Pesticide Applicator Training Manual
Burns, Boyd (Bo) D (2020-12-06). "Insect Bites: Background, Pathophysiology, Epidemiology". Medscape Reference. Retrieved 2021-01-22.