A 48-year-old man comes to the office due to concern that his skin is excessively dry, red, and cracked. The patient explains that he washes his hands each time he touches something due to fear of contamination. He spends 3-4 hours a day washing his hands and showers multiple times daily. He was recently fired from his job after refusing to touch keyboards shared by coworkers and is worried that he will be unable to find employment. On physical examination, the palms are erythematous with peeling skin. Treatment of this patient's disorder is most likely to involve a medication affecting which of the following neurotransmitters?

Question

A 48-year-old man comes to the office due to concern that his skin is excessively dry, red, and cracked.  The patient explains that he washes his hands each time he touches something due to fear of contamination.  He spends 3-4 hours a day washing his hands and showers multiple times daily.  He was recently fired from his job after refusing to touch keyboards shared by coworkers and is worried that he will be unable to find employment.  On physical examination, the palms are erythematous with peeling skin.  Treatment of this patient's disorder is most likely to involve a medication affecting which of the following neurotransmitters?

Quizplus · Accepted Answer

11ec160b_3c54_bc20_9249_332b03e01e42_MD0001_00 This patient's fear of contamination leading to compulsive washing rituals is consistent with obsessive-compulsive disorder (OCD). OCD is characterized by obsessions or compulsions, with most patients experiencing both. Common themes include contamination obsessions with cleaning compulsions; obsession with symmetry and compulsions involving ordering and counting; and fear of harm with checking compulsions (eg, stove off, doors locked). Patients with OCD typically engage in time-consuming rituals (>1 hr/day) that cause significant distress and/or functional impairment. Patients with washing compulsions may present with skin conditions. Selective serotonin reuptake inhibitor (SSRI) antidepressants are considered first-line treatment for OCD. SSRIs block the reuptake of serotonin into the presynaptic neuron, leading to an immediate increase in availability of synaptic serotonin and a subsequent cascade of downstream neurobiological effects. (Choice A) In the central nervous system, acetylcholine is involved primarily in arousal, memory, and learning. Degeneration of cholinergic neurons is associated with Alzheimer dementia. (Choices B and D) There is evidence for dysfunction of the dopamine and glutamate (primary excitatory neurotransmitter) systems in the pathogenesis of OCD; however, neither neurotransmitter is a significant target of first-line medications. (Choices C and E) Gamma-aminobutyric acid is the primary inhibitory neurotransmitter in the central nervous system and is involved in the anti-anxiety effects of benzodiazepines. Glycine is also an inhibitory neurotransmitter. (Choice F) Histamine is a neurotransmitter involved in maintaining wakefulness and, as a result, drugs with antihistamine properties may be sedating. (Choice G) Norepinephrine is a catecholamine involved in mood, anxiety, alertness, learning, and memory. Educational objective: Obsessive-compulsive disorder (OCD) is characterized by persistent, intrusive thoughts leading to repetitive, ritualistic behaviors. Selective serotonin reuptake inhibitors are considered first-line treatment for OCD and exert their effects by inhibiting serotonin reuptake. __________ References: Obsessive-compulsive disorder: advances in diagnosis and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/28384832) Obsessive-compulsive disorder. (http://www.ncbi.nlm.nih.gov/pubmed/24576790)

A 48-Year-Old Man Comes to the Office Due to Concern