What could be causing a crawling sensation in my lower legs and feet, upper back, and arms, accompanied by facial flushing and a feeling of being disoriented?

Crawling Sensations with Facial Flushing and Disorientation: Diagnostic Approach

Your symptoms most likely represent either Restless Legs Syndrome with upper body involvement or a medication-induced akathisia, though anaphylaxis and migraine with sensory aura must be urgently excluded based on the facial flushing and disorientation. 1, 2

Immediate Red Flag Assessment

First, determine if this is an acute emergency requiring immediate intervention:

• Anaphylaxis must be excluded immediately if facial flushing is accompanied by urticaria, angioedema, pruritus, hypotension, tachycardia, or respiratory symptoms. 1 The combination of crawling sensations (pruritus), facial flushing, and feeling "out of it" can represent early anaphylaxis. 1

• Vertebrobasilar insufficiency can present with paresthesias and lightheadedness that may precede stroke by weeks or months. 2 If you have dysarthria, dysmetria, dysphagia, or any motor/sensory loss, urgent neuroimaging is mandatory. 2

• Migraine with sensory aura presents as "pins and needles" that spread gradually over ≥5 minutes, last 5-60 minutes, and can be unilateral. 2 Vestibular migraine accounts for 14% of adult vertigo cases and can occur without headache. 2, 3

Primary Diagnostic Considerations

Restless Legs Syndrome (RLS) with Upper Body Extension

RLS is characterized by crawling, tingling, or aching sensations creating an urge to move, worsening at rest and in the evening. 1, 4

• The crawling sensation in your lower legs and feet is the classic presentation of RLS, described as "creepy-crawly, burning, itching or even painful feeling." 1

• Upper extremity involvement occurs in RLS, though less commonly discussed. 1 Restless arm syndrome (RAS) has been documented as a variant affecting predominantly the arms. 5

• Restless back syndrome has been reported with uncomfortable pain, burning, ant crawling, or itching sensations in the back. 6

• RLS affects approximately 10% of Caucasian populations, is more common in women (2:1), and worsens through the first seven decades of life. 1, 7

• Symptoms characteristically worsen at night and improve with movement such as walking, rubbing, or stretching. 1

Medication-Induced Akathisia

If you are taking antipsychotic medications, SSRIs, tricyclic antidepressants, lithium, or dopamine antagonists, akathisia is a leading diagnosis. 1

• Akathisia presents as a subjective feeling of restlessness that generally occurs within the first few days of antipsychotic medication therapy. 1

• This can manifest as crawling sensations and an irresistible urge to move. 1

• Facial flushing is not typical of akathisia alone but could represent concurrent autonomic dysfunction. 1

Vasodepressor (Vasovagal) Reaction

The combination of feeling "out of it" with facial flushing could represent a vasovagal episode, though this typically presents with pallor rather than flushing. 1

• Vasovagal reactions include hypotension, weakness, nausea, and diaphoresis. 1

• These can be distinguished from anaphylaxis by lack of urticaria, angioedema, and the presence of bradycardia instead of tachycardia. 1

Essential Diagnostic Workup

History Elements to Clarify

Document the following specific details:

• Timing: Do symptoms worsen in the evening/night and improve with movement? This strongly suggests RLS. 1, 7

• Medication review: List all medications including antipsychotics, antidepressants, antihistamines, and dopamine antagonists. 1

• Triggers: Are symptoms triggered by head rotation (cervicogenic), position changes, or rest? 2, 8

• Duration and spread: Do sensations spread gradually over ≥5 minutes (migraine aura) or occur simultaneously? 2

• Associated symptoms: Urticaria, angioedema, respiratory symptoms (anaphylaxis); headache (migraine); urge to move (RLS). 1, 2

Laboratory Testing

Obtain the following labs to identify secondary causes of RLS:

• Serum ferritin and iron studies: Iron deficiency is a major cause of secondary RLS. 1, 7

• Complete blood count: To assess for anemia. 1

• Comprehensive metabolic panel: To evaluate for renal failure, which is associated with RLS. 1, 7

• Thyroid function tests: Thyroid tumors can cause flushing episodes. 1

• If anaphylaxis suspected: Serum tryptase (peaks 60-90 minutes after onset, persists to 6 hours). 1

Imaging Considerations

Imaging is NOT routinely indicated for RLS or akathisia. 1

However, MRI brain with and without contrast is indicated if:

• Neurological deficits are present (dysarthria, dysmetria, dysphagia, sensory/motor loss). 2

• Symptoms suggest central pathology rather than peripheral sensory phenomena. 2

• The diagnostic yield of imaging in nonspecific dizziness without vertigo, ataxia, or neurologic deficits is extremely low (<1% for CT, 4% for MRI). 2, 3

Treatment Algorithm

If RLS is Confirmed

First-line treatment is dopamine receptor agonists (e.g., rotigotine patch, pramipexole, ropinirole). 4, 7

• Rotigotine (Neupro) patch has significantly lower rates of augmentation compared to other dopamine agonists. 4

• Gabapentin enacarbil (Horizant) is the only FDA-approved nondopaminergic medication for RLS and does not cause augmentation. 4

• Correct iron deficiency: If ferritin <75 mcg/L, iron supplementation is indicated. 7

• Alternative options include gabapentin, opioids, or benzodiazepines. 7, 9

If Medication-Induced Akathisia

Reduce or discontinue the offending antipsychotic medication. 1, 6

• Switch from typical to atypical antipsychotic if possible. 1

• Add an anticholinergic agent (e.g., benztropine) or dopaminergic agonist (amantadine). 1

• Restless back syndrome specifically may remit with dose reduction of amisulpride or aripiprazole. 6

If Migraine with Sensory Aura

Migraine prophylaxis and trigger avoidance are recommended. 2, 3

• Consider triptans for acute episodes if headache component is present. 2

• Vestibular rehabilitation may be beneficial for vestibular migraine. 3

Critical Pitfalls to Avoid

• Do not dismiss upper body involvement as "not RLS": RLS can affect arms, back, and even trunk, though less commonly recognized. 1, 5, 6

• Do not assume all crawling sensations are RLS: Medication-induced akathisia, peripheral neuropathy, and anaphylaxis can mimic these symptoms. 1

• Do not overlook iron deficiency: Even without anemia, low ferritin can cause or worsen RLS. 1, 7

• Do not ignore the facial flushing: This is NOT typical of RLS and requires evaluation for anaphylaxis, carcinoid syndrome, pheochromocytoma, or medication effects (niacin, alcohol, ACE inhibitors). 1

• Do not routinely image for RLS: Imaging is only indicated if neurological deficits suggest central pathology. 2, 3