خلايا النحل

أسباب

Hives are often caused when the body releases a chemical called histamine. Histamine is released during an allergic reaction. Many people, though, get hives without being exposed to something they are allergic to.

While the cause is unknown in some cases, these factors may cause hives:

• Foods, most commonly:
  • بيض
  • المحار
  • Nuts
  • الشوكولاته
  • سمكة
  • Tomatoes
  • Fresh berries
  • Milk
• الأدوية
• Reaction to allergy shots (desensitization shots)
• الالتهابات
• Insect bites or stings
• مطاط
• Pressure
• Cold or heat
• ضوء الشمس
• Thyroid disease (hypothyroidism, hyperthyroidism)
• لقاح
• ضغط
• Vasculitis (inflammation of the blood vessels)

عوامل الخطر

A risk factor is something that increases your chance of getting hives. Tell your doctor if you have any of these:

• Exposure to an allergen (something that causes an allergic reaction)
• Exposure to an allergen that triggered hives in the past

الأعراض

Symptoms of hives can vary from mild-to-severe:

• Itchiness
• احمرار
• تورم
• Excessive swelling of the eyelids, lips, or genitals
• Burning
• Stinging
• Difficulty breathing or swallowing—Call 911 if you are having these symptoms.

التشخيص

The doctor will ask about your symptoms and medical history, and do a physical exam. You may need to see a doctor who specializes in skin disorders (dermatologist) or allergies (allergist). The following tests will be done:

• Skin prick test—a tiny bit of an allergen is placed in your skin with a needle to see if the area becomes raised or irritated
• Skin biopsy—a small portion of abnormal skin is removed
• الأشعة السينية - اختبار يستخدم الإشعاع لالتقاط صورة للبنى داخل الجسم ، وخاصة العظام
• تحاليل الدم

العلاج

The best way to treat hives is to find and then avoid the cause.

If the cause can’t be found, there are medicines to reduce symptoms or treat hives:

• H1-blocking medicines like:
  • Diphenhydramine (eg, Aler-Cap, Benadryl Allergy)
  • Hydroxyzine (eg, Vistaril)
  • Cyproheptadine
  • Fexofenadine (eg, Allegra)
  • Loratadine (eg, Claritin)
  • Acrivastine (eg, Semprex)
  • Cetirizine (eg, Zyrtec)
  • Doxepin (eg, Prudoxin, Sinequan, Zonalon)
  • Levocetirizine (eg, Xyzal)
• H2 blocking medicines like:
  • Cimetidine (eg, Tagamet HB)
  • Ranitidine (eg, Zantac)
  • Famotidine (eg, Pepcid)
• Leukotriene antagonists like Montelukast
• Oral steroid medications (eg, prednisone) for hives resistant to other treatments
• Anti-inflammatory medicines
• Immunosuppressant medicines
• Ultraviolet light therapy
• Prescription epinephrine (adrenalin) injections for cases when swelling affects the airways

الوقاية

The best way to prevent hives is to avoid allergen that caused you to get hives in the past.