Sports Medicine: Just the Facts

CHAPTER 37 • ALLERGIC DISEASES IN ATHLETES 225

4. Solar urticaria occurs with exposure to ultraviolet
   light. Anaphylaxis could occur if large body areas
   are exposed.
   5.Pressure urticaria (angioedema) is precipitated by
   direct pressure on the skin. Skin pressure is followed
   3–12 h later by localized hives, fever, malaise, and
   leukocytosis. It can be precipitated by running,
   clapping, sitting, or using hand equipment.
   Symptoms can last up to 24 h.
   6.Symptomatic dermatographism is another type of
   physical urticaria. Patients develop linear, pruritic
   wheals 2–5 min after an area of skin is stroked.

EVALUATION

• In the acute setting, providers should assess for symp-
  toms indicating anaphylaxis rather than isolated
  urticaria or angioedema. (See Anaphylaxis and Ana-
  phylactoid Reactions.)


• While in most cases the precipitant remains unknown,
  a detailed history may isolate the cause. Searching for
  a trigger is more beneficial in acute urticaria as com-
  pared to chronic urticaria where the cause is found in
  less than 10% of cases. For known causes, drug
  hypersensitivity is most common. Individuals should
  be asked about any recent prescription, over-the-
  counter medications, or supplement use. Food and
  food additives rarely cause isolated urticaria, but the
  relationship to food inhalation, contact, and consump-
  tion should be documented. It is important to docu-
  ment physical triggers, occupational exposures, insect
  envenomations, and any recent illnesses. A thorough
  review of systems will help rule out any disease asso-
  ciations, such as an acute bacterial or viral illness, par-
  asitic infection, autoimmune/collagen vascular
  disease, serum sickness, endocrine disease, or malig-
  nancy (Stafford, 1990).


• The physical examination is especially helpful in the
  acute setting when skin manifestations are present. It
  can help document whether urticaria and
  angioedema are occurring together or in isolation
  and whether there are any signs of anaphylaxis. The
  examination should also look for evidence of other
  diseases that are rarely associated with urticaria and
  angioedema.


• The use of laboratory and imaging studies should be
  targeted by the history and physical. Consider the
  following tests: Monospot or Epstein-Barr virus
  antibody titers if acute mononucleosis is suspected;
  Hepatitis A, B, and C panel; and HIV testing given the
  right clinical setting. The association of urticaria with
  other viral infections remains unclear and routine test-
  ing for other viral pathogens is not recommended.
  
  
  • If a significant travel history is discovered and the
    complete blood count shows eosinophilia, stool stud-
    ies should be obtained looking for intestinal parasites.
    Progressive weight loss and/or the presence of lympa-
    denopathy or hepatosplenomegaly on examination
    would warrant an evaluation for an underlying lym-
    phoreticular malignancy.
  
  
  • If enlargement or nodularity of the thyroid is present,
    a thyroid function panel, thyroid autoantibodies, thy-
    roid ultrasound, and nuclear medicine thyroid studies
    should be considered.
    •Testing for C1 esterase inhibitor deficiency should be
    considered for any athlete presenting with recurrent
    isolated angioedema.
    •A skin biopsy for vasculitis is indicated when individ-
    ual urticarial lesions last longer than 24 h or are asso-
    ciated with purpura, pain, hyperpigmentation, or
    systemic symptoms (Kaplan, 1993).
  
  
  • If the history and physical examination are unreveal-
    ing, a limited laboratory evaluation consisting of a
    complete blood count with differential, urinalysis,
    erythrocyte sedimentation rate and liver panel is rea-
    sonable to screen for occult conditions.
  
  
  
  

MANAGEMENT

• After the initial evaluation, the management of
  urticaria and angioedema becomes primarily sympto-
  matic. Known triggers should be avoided if possible.
  Mild symptoms can be controlled with a low sedating
  antihistamine (see Table 37-1). Athletes with exercise-
  induced symptoms only, such as cholinergic urticaria,
  can take the antihistamine 1–2 h prior to exercise.
  Those who exercise regularly and those with chronic
  symptoms often require daily medication to prevent
  exacerbations. For moderate or poorly controlled
  symptoms, the antihistamine dose should be maxi-
  mized prior to considering add-on therapy. Additive
  therapies include leukotriene antagonists, H-2 block-
  ers and nighttime doxepin. For periods of moderate to
  severe symptoms prednisone therapy can be helpful.


• Because food and food additives are a rare cause of
  chronic urticaria and angioedema, elimination diets
  are unnecessary unless the history pinpoints a specific
  food.
  •Referral to an allergist is recommended when there is
  suspicion of an allergic component precipitating
  symptoms, when symptoms are not well controlled
  with the therapies listed above, when there is a history
  of respiratory distress or hypotension suggesting ana-
  phylaxis, or when there is severe angioedema. The
  athlete should be referred to dermatology for skin
  biopsy if urticarial vasculitis is suspected.