Definitions
A cutaneous reactivity manifest by transient wheals and transudation of fluid from small cutaneous vessels. Usually involves pruritis and may be triggered by immune, IgE and non immune hypocomplement, and physical stimuli factors. Urticaria are hives of the epidermis and angiodema, the edematous areas of dermis, and subcutaneous layers. There are more than seven types of urticaria-angioedema.
History
Symptoms: Transient wheals, welts, hives. Pruritis, pain with walking (when the feet are involved), flushing, burning at various involved sites.
General: May have systemic symptoms in a minority of cases (e.g., wheezing [in cholinergic urticaria], fever especially in serum sickness, hoarseness, stridor, dyspnea, arthralgia). These symptoms develop rapidly in anaphylaxis, an alarming hypersensitivity state.
Age: Any.
Onset: Acute within minutes to hours, or chronic over hours to days.
Duration: Hours; with transiep,t recurring flares. Acute last less than 30 days, but for chronic over 30 days to months.
Intensity: Localized, regional or generalized.
Aggravating Factors: Stroking the skin or linear means of pressure in dermographism. Cold contact or cold submersion in cold urticaria. Sun exposure for minutes to reactive skin in uncommon solar urticaria. Heat, emotional stress or exercises in cholinergic urticaria. Any repetitive rubbing (e.g., drying the back) or any mechanical vibrations in vibratory angioedema. Persistent pressure to feet, buttocks, or palms in pressure urticaria. Minor trauma or no detectable irritants may flare episode of hereditary angioedema. Third trimester of pregnancy leads to pruritic urticarial papules and plaques of pregnancy in some. Contact penetration or ingestion of offending drugs, food, inhalant allergens, or infection, bites of insects or arthopods, internal disease, and psychogenic stress factor trigger allergic urticaria and angioedema. Water contact in aquagenic urticaria.
Alleviating Factors: Avoidance of offending trigger factors.
Associated Factors: Familial propensity, systemic disease, infections, and emotional stress exacerbates the condition.
Physical Examination
Skin: Many wheal papules, 1 to 2 mm, located on the trunk and extremities in cholinergic type. Small, 1-cm wheals to large 8-cm edematous plaques on the trunk or extremities, including hands and feet, face, lips, tongue, and ears. Skin-colored enlargement of eyelids, lips, and tongue are common in angioedema. Other lesions are pink to red with larger lesions having a pale central halo-like area. The lesions are roundish, oval, arciform, annular, polycyclic, serpiginous, and bizzare in pattern shapes. They are arranged in annular, arciform, linear, local, or wide areas including pressure and exposed areas depending on the type of urticaria.
Pathophysiology
Biologically active materials from mast cells and/or basophilic leukocytes sensitized with IgE antibodies causes acute urticaria. Mediators cause increased venule permeability and some are not related to immunologic factors but to non immunologic factors such as drugs, compounds capable of histamine release, or physical agents including trauma. Activation of the complement system plays a role in type III immune complexes involved in serum sickness urticaria and that of connective tissue-vascular disease. HI and H2 receptors are both involved and the histamine release leads to the erythema, wheal-flare, and pruritis.
Diagnostic Studies
Laboratory
Chemistry profile: As a baseline.
Complete blood count with differential: As a baseline.
Erythrocyte sedimentation rate: As a baseline.
Radiology: Not applicable.
Other: Not applicable.
Differential Diagnosis
Traumatic
Traumatic wheal-flare: Is reproduce able with physical factor contact (e.g., ice, heat, pressure, stroking).
Infectious
Secondary syphilis: RPR or Venereal Disease Research Laboratories (VDRL) positive.
Streptococcus/Candidiasis: Will have positive smears or cultures.
Metabolic
Cholinergic urticaria: Provoked by exercising or sweating.
Neoplastic: Not applicable.
Vascular
Vasculitidies: Will have more petechial, purpuric, or dark purple lesions. Any hive-like lesions are not transient but persistent and called urticaria perstans, a feature of necrotizing vasculitis. Also feature nodules, and necrotic ulcers.
Erythema nodosum: Typically in durations of subdermal nodules tender and not as transient.
Erythema multiforme: Classic iris target lesions of palms, soles, hands, feet, forearms, elbows, mouth, lips, eyes, and penis. Lungs affected 30 percent of the time.Each of the above is a reactive vascular condition caused by idiopathic factors, infections, or drugs.
Congenital: Not applicable.
Acquired: Not applicable.
Treatment
Anaphylaxis and hereditary angioedema may lead to life-threatening laryngeoedema and require urgent emergent care. Actue and chronic urticarias generally diminish with time regardless of the etiology.
First-line treatment is elimination of etiologic factors such as chemicals or drugs. Next, an HI antihistamine such as Hydroxyzine HC1 25 to 50 mg 2 to 4 times a day in adults or a nonsedating HI such as terfenadine, astemizole, or loratadine 1 tablet every 12 to 24 hours.
If unsuccessful, an HI from different class may be selected. Cyproheptadine is the most effective in cold urticaria 2 to 4 times daily. Next add doxepin 25 to 75 mg at bedtime (adults). If no response add an H2 blocker such as cimetidine 400 mg three times a day or 800 mg at bedtime in adults or ranitidine 150 mg twice a day. If no response, add pseudoephedrine 30 mg every day. Prednisone 40 to 60 mg every day times 2 weeks and tapered to 10 to 20 mg Q.O.D. before stopping, may be required in severe disease. Remember even the worst cases will probably resolve in a few months.
Pediatric Consideration
Vascular disorders occur in 20 to 40 percent of newborns. They may occur as isolated defects, be confined to the skin, or they may be a feature of various syndromes.
The salmon patch is the most common vascular lesion of infancy. Common sites include the nape of the neck (stork bite), upper eyelids, and glabella. Ninety-five percent of those appearing on the eyelids or glabella disappear within the first year and 50 percent of those found on the neck resolve spontaneously. Port wine stains, dark red or purple macules present at birth, appear unilaterally on the side of the face or an extremity. A port wine stain, found on the face in the distribution of the ophthalmic branch of the trigeminal nerve or associated with hemihypertrophy of the side of the face, should suggest Sturge-Weber syndrome. If found over an extremity and in combination with bony and soft tissue hypertrophy and venous varicosities, Klippel-Trenaunay Weber syndrome is suggested.
Strawberry hemangiomas are characterized as bright red, raised, and well-circumscribed. Most are not present at birth but appear within the first 2 months. The most common sites include the face, scalp, and thorax. Often the lesions represent a mixture of capillary and venous elements. Hemangiomas grow rapidly during the first 6 months and most do not enlarge after 12 months. A spontaneous process of involution then begins and 50 percent resolve by age 5, 90 percent by age 9, and the rest by adolescence. In general no treatment is necessary. Mild complications include ulceration and pyoderma. More serious complications can occur when platelet trapping within the lesion results in thrombocytopenia (Kasabach-Merritt Syndrome) or when location or size compromise vital structures (e.g., airway obstruction, visual obstruction).
Cavernous hemangiomas are more deeply situated lesions and appear more diffuse and ill-defined. They are cystic, firm and the overlying skin may appear bluish in color. Rarely, do these tumors impinge on vital structures, but if involvement of underlying structures IS suspected, appropriate radio logic studies should be performed.
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