Urticaria Clinical Presentation

Information regarding history of previous urticaria and duration of rash and itching is useful for categorizing urticaria as acute, recurrent, or chronic.

• For chronic or recurrent urticaria, important considerations include previous causative factors and the effectiveness of various treatments.^[2]
• Ask about precipitants, such as heat, cold, pressure, exercise, sunlight, emotional stress, or chronic medical conditions (eg, hyperthyroidism, systemic lupus erythematosus [SLE], rheumatoid arthritis, polymyositis, amyloidosis, polycythemia vera, lymphoma and other malignant neoplasms).
• Ask about other medical conditions that can cause pruritus (usually without rash), such as diabetes mellitus, chronic renal insufficiency, primary biliary cirrhosis, or other nonurticarial dermatologic disorders (eg, eczema, contact dermatitis).
• Ask about family and personal medical history of angioedema, which is urticaria of the deeper tissues and can be life threatening if it involves the larynx and vocal cords. Causes specific to angioedema include hereditary angioedema (a deficiency in C1-inhibitors) and acquired angioedema (associated with angiotensin-converting enzyme [ACE] inhibitors and angiotensin receptor blockers (ARBs). Characteristics of angioedema include the following:^[3]

  • Vasodilation and exudation of plasma into deeper tissues than is seen in simple urticaria
  • Swelling that is generally nonpitting and nonpruritic and usually occurs on the mucosal surfaces of the respiratory tract (lips, tongue, uvula, soft palate, and larynx) and GI tract (swelling of the intestine leading to severe abdominal pain)
  • Hoarseness, the earliest sign of laryngeal edema (Ask the patient if he or she has had a voice change.)
• For acute urticaria, ask about possible precipitants, such as the following:^[3]

  • Recent illness (eg, fever, sore throat, cough, rhinorrhea, vomiting, diarrhea, headache)
  • Medication use including penicillins, cephalosporins, sulfas, diuretics, aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), iodides, bromides, quinidine, chloroquine, vancomycin, isoniazid, antiepileptic agents, and other agents
  • Intravenous radiocontrast media
  • Travel (amebiasis, ascariasis, strongyloidiasis, trichinosis, malaria)
  • Foods (eg, shellfish, fish, eggs, cheese, chocolate, nuts, berries, tomatoes)
  • New perfumes, hair dyes, detergents, lotions, creams, or clothes
  • Exposure to new pets (dander), dust, mold, chemicals, or plants
  • Pregnancy (usually occurs in last trimester and typically resolves spontaneously soon after delivery)
  • Contact with nickel (eg, jewelry, jeans stud buttons), rubber (eg, gloves, elastic bands), latex, industrial chemicals, and nail polish
  • Sun or cold exposure
  • Exercise

Urticaria is characterized by blanching, raised, palpable wheals, which can be linear, annular (circular), or arcuate (serpiginous). These lesions occur on any skin area and are usually transient and migratory. These lesions are often separated by normal skin, but may coalesce rapidly to form large areas of erythematous, raised lesions that blanch with pressure.

• Dermographism may occur (urticarial lesions resulting from light scratching).
• The physical examination should focus on conditions that might precipitate urticaria or could be potentially life threatening.^[3]

  • Angioedema of the lips, tongue, or larynx
  • Individual urticarial lesions that are painful, long lasting (longer than 36-48 h), or are ecchymotic; also, urticarial lesions that leave residual hyperpigmentation or ecchymosis upon resolution (suggesting urticarial vasculitis)
  • The presence of systemic signs or symptoms, particularly fever, arthralgias, arthritis, weight changes, bone pain, or lymphadenopathy
  • Scleral icterus, hepatic enlargement, or tenderness that suggests hepatitis or cholestatic liver disease
  • Thyromegaly suggesting autoimmune thyroid disease; joint examination for any evidence of connective tissue disease, rheumatoid arthritis, or systemic lupus erythematosus (SLE)
  • Lungs for pneumonia or bronchospasm (asthma)
  • Skin for evidence of bacterial or fungal infection

• The cause of acute generalized urticaria often is undetermined (some sources report that the cause is undetermined in more than 60% of cases). Known causes include the following:

  • Infections (eg, pharyngitis, GI infections, genitourinary infections, respiratory infections, fungal infections [eg, dermatophytosis], malaria, amebiasis, hepatitis, mononucleosis, coxsackievirus, mycoplasmal infections, infestations [eg, scabies], HIV, parasitic infections [eg, ascariasis, strongyloidiasis, schistosomiasis, trichinosis]).
  • Caterpillars and moths^[12]
  • Foods (particularly shellfish, fish, eggs, cheese, chocolate, nuts, berries, tomatoes)
  • Drugs (eg, penicillins, sulfonamides, salicylates, NSAIDs, codeine, antihistamines)
  • Environmental factors (eg, pollens, chemicals, plants, danders, dust, mold)
  • Exposure to latex
  • Exposure to undue skin pressure, cold, or heat
  • Emotional stress
  • Exercise
  • Pregnancy (ie, pruritic urticarial papules and plaques of pregnancy [PUPPP])
• Chronic urticaria can be related to all of the above as well as to the following:

  • Autoimmune disorders (SLE, rheumatoid arthritis, polymyositis, thyroid autoimmunity, and other connective tissue diseases); probably up to 50% of chronic urticaria is autoimmune^{[13, 11, 14, 9]}
  • Cholinergic urticaria induced by emotional stress, heat, or exercise; examine for other signs of cholinergic stimulation including lacrimation, salivation, and diarrhea.^[8]
  • Chronic medical illness, such as hyperthyroidism, amyloidosis, polycythemia vera, malignant neoplasms, lupus, lymphoma, and many others^[15]
  • Cold urticaria, cryoglobulinemia, cryofibrinogenemia, or syphilis^[8]
  • Mastocytosis^[16]
  • Inherited autoinflammatory syndromes^[17]
  • The etiology of chronic urticaria is undetermined in at least 80-90% of patients.^[18]
• Urticaria pigmentosa is a familial dermatologic disorder characterized by hyperpigmented (yellow, tan, or brown) papules or plaques that may be associated with lymphoproliferative disorders. These lesions are composed of mast cells. When the skin overlying an individual lesion of urticaria pigmentosa is stroked, a linear wheal is formed; this characteristic and diagnostic sign is known as the Darier sign.^[19]
• Recurrent urticaria can be related to the following:

  • Sun exposure -solar urticaria, occurring only on skin exposed to the sun^[20]
  • Exercise (cholinergic urticaria)
  • Emotional or physical stress
  • Water (aquagenic urticaria)