Urticaria Pigmentosa

At a glance

Major variant and most common type of cutaneous mastocytosis. Typically presents in childhood as discreet hyperpigmented cutaneous macules that flare and wheal on superficial stimulation (Darier sign). Degranulation must be avoided during all anesthetic procedures (physiological and psychological stress, drugs).

Synonyms

Urticaria Perstans Hemorrhagica with Pigmentosa; Localized Infantile Mastocytosis; Nettleship E Disease Type I; Xanthelasmoidea; Chronic Urticaria.

Incidence

Estimated 1:150,000. Most often seen in children; however, it can also occur in adults. It affects males and females equally.

Genetic inheritance

Both autosomal and recessive inheritance have been evocated; however, sporadic cases have also been reported.

Pathophysiology

Unknown. When mast cells proliferate, histamine and heparin are released into the skin. Mastocytosis presents with characteristic skin lesions of urticaria and telangiectasis.

Diagnosis

Urticaria pigmentosa is a localized form of mastocytosis. It is generally benign and is usually self-limited. Diagnosis is clinically evocated in a child older than age 2 years with skin lesions affecting the neck, arms, legs, and trunk. The rash consists of reddish-brown spots that turn into hives when they are rubbed hard or scratched. Certitude diagnosis can be obtained with skin biopsy.

Clinical aspects

Skin lesions can also include bullous mastocytosis and telangiectasia macularis eruptiva perstans (multiple hyperpigmented telangiectatic macules, located primarily on the trunk and on the extremities). In the early form, resolution of the condition by adolescence or early adulthood is common. In the form beginning after 5 years of age, the abnormal collections of mast cells sometimes involve other organs. It can affect bone, gastrointestinal tract, lymphatics, spleen, and liver, resulting in clinical signs such as abdominal pain or gastric ulcer. It is even possible to observe an overgrowth of mast cells progressing to a malignant out-of-control process called mast cell leukemia. Mast cells can abruptly release vasoactive mediators, such as histamine, heparin, and prostaglandins, under some physical stresses or in response to drugs. Severe general reaction with shock can occur. Degranulation episodes can decrease in both severity and frequency with advancing age. Patients frequently suffer from reactive depression.

Precautions before anesthesia

Obtain full medical and physical history. One must review the signs and symptoms of previous cardiovascular instability, ie, hypotension, loss of consciousness, vomiting, and severe flushing and sweating. Evaluate organ involvement (clinical, ultrasound).

Anesthetic considerations

Both regional and general anesthesia can produce life-threatening complications. Avoid mastocyte degranulation (eg, mild temperature in the operating room), psychological and physical stress. Resuscitation drugs should be present in the operating room. It is recommended to be very careful with the insertion of nasal tubes as it may cause early bruising and severe nose ...