Differential Diagnosis for a Patient with Anxiety and Muscle Movement Under the Skin

• Single most likely diagnosis:
  • Anxiety disorder with somatic symptoms: The patient's complaint of feeling muscles move under her skin could be a manifestation of anxiety, where the physical symptoms are a result of the psychological distress. This is a common presentation in clinical practice.
• Other Likely diagnoses:
  • Hypnagogic jerks or fasciculations: These are involuntary muscle twitches that can be benign but might be perceived as muscles moving under the skin, especially in a state of heightened anxiety.
  • Restless Leg Syndrome (RLS): Characterized by an irresistible urge to move the legs, often accompanied by uncomfortable sensations, which could be misinterpreted as muscles moving under the skin.
  • Tardive dyskinesia: Although less common, this condition involves involuntary, repetitive body movements that could be perceived as muscles moving, especially if the patient has a history of antipsychotic medication use.
• Do Not Miss diagnoses:
  • Neuroleptic Malignant Syndrome (NMS): A life-threatening neurological disorder most often caused by an adverse reaction to neuroleptic or antipsychotic medication. Early symptoms can include muscle rigidity and involuntary movements.
  • Serotonin Syndrome: Another potentially life-threatening condition that occurs when there is too much serotonin in the body, often due to certain medications. Symptoms can include muscle rigidity and twitching.
• Rare diagnoses:
  • Ehlers-Danlos Syndrome: A group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and many other organs and tissues. Some types can lead to hypermobile joints and potentially unusual sensations in the skin.
  • Morgellons disease: A rare condition characterized by the presence of fibers or other materials under the skin, which could be perceived as muscles moving. However, its existence and nature are controversial within the medical community.