What is vibratory urticaria?
Vibratory urticaria is an uncommon form of chronic inducible urticaria in which urticarial weals follow a vibratory stimulus to the skin.
Vibratory urticaria and vibratory angioedema (angioedema due to a vibratory stimulus) were considered a single entity, but are now considered to be distinct clinical disorders.
Who gets vibratory urticaria?
Vibratory urticaria is amongst the rarest forms of chronic inducible urticaria. Sporadic and hereditary variants have been documented, with familial cases transmitted with an autosomal dominant pattern.
Sub-clinical vibratory urticaria, in which mild symptoms develop on exposure to vibration, may be quite common as it has been reported in up to one-quarter of a sample of 172 young adults. In this study females reported symptoms more often than males.
What causes vibratory urticaria?
In patients with vibratory urticaria, a vibratory stimulus activates mast cells to release histamine and other inflammatory mediators.
- Degranulation of superficial mast cells results in weals/urticaria.
- Degranulation of deeper sub-dermal mast cells results in angioedema.
The exact pathophysiology is not well understood. However, some familial cases have been linked to a mutation in the ADGRE2 gene.
Triggers associated with vibratory urticaria include:
- Power-tools, including drills, jackhammers, and metal grinders
- Cycling/riding over cobblestones
- Lawn mowing
- Horseback riding
- Towelling or massaging.
What are the clinical features of vibratory urticaria?
Vibratory urticaria presents within minutes of exposure to a vibratory stimulus and usually lasts for 1–2 hours.
- Itch, redness and swelling is localised to the site of the stimulus.
- Weals most often appear on the hands and trunk, the parts of the body most exposed to vibration stimuli.
- The weals cause itching, burning, and prickling sensations.
What are the complications of vibratory urticaria?
Systemic progression of vibratory urticaria may rarely occur after extensive exposure to a vibratory stimulus. Symptoms may include:
- Generalised erythema
- Hypotension
- Headaches
- Dizziness.
Anaphylaxis has been associated with vibratory angioedema, but has not been documented with vibratory urticaria. Vibratory urticaria has not been reported as a cause of death.
How is vibratory urticaria diagnosed?
A clinical diagnosis of vibratory urticaria is made in a patient reporting wealing after exposure to vibratory stimuli. Vibratory urticaria can be confirmed by provocation testing.
Vibration provocation test
A non-standardised vibratory provocation test is conducted as follows:
- Apply a vortex or mixer on a level plane with the forearm skin
- Apply the vibration stimulus for at least 5 minutes
- Assess the skin for urticaria.
The speed of the vortex, the time, and the pressure required to induce a response are variable.
Patients should not take antihistamines for several days before the test.
What is the differential diagnosis for vibratory urticaria?
Vibratory urticaria should be distinguished from other causes of angioedema and urticaria, including:
- Vibratory angioedema (swelling due to a vibratory stimulus)
- Symptomatic dermographism (wealing on stroking the skin)
- Aquagenic urticaria (wealing due to contact with water)
- Cold urticaria (wealing due to contact with a cold object or cold air)
- Contact urticaria (eg, wealing due to contact with a stinging nettle).
What is the treatment for vibratory urticaria?
Patients should avoid contact with vibratory stimuli, including at work, bearing in mind the risk of systemic involvement after prolonged or generalised exposure.
Vibratory urticaria episodes can be prevented with a prophylactic non-sedating antihistamine, such as cetirizine or loratadine.
What is the outcome for vibratory urticaria?
The prognosis for patients with vibratory urticaria is reported to be excellent, however remission rates are unknown.
Vibratory urticaria usually resolves with avoidance of vibratory stimuli and treatment with antihistamines.