| What is urticaria? | • Urticaria refers to a group of disorders affecting adults and children, in which red patches and wheals occur in the skin
• The name urticaria is derived from the common European
stinging nettle 'Urtica dioica |
| How are wheals (papules) of urticaria present? | The skin swelling seen in urticaria is due to the release of histamine from mast cells and basophils in the skin, which causes small blood vessels to leak
The wheal (papule) can be a few millimeters or several centimeters in diameter, colored white or red, often surrounded by a red flare, and frequently itchy
Each wheal may last a few minutes or several hours and may change shape.
Wheal may be round, or form rings, a map-like pattern or giant patches |
| What are associated conditions in urticaria? | • The surface wheals may be accompanied by deeper swelling of eyelids, lips, hands and elsewhere. The deeper swelling is called angioedema
• Angioedema may occur with or without urticarial wheals (10%)
• Rarely, urticaria results from an autoinflammatory disease such as systemic lupus or Schnitzler syndrome, or an inherited condition such as Muckle-Wells syndrome
• Schnitzler syndrome: chronic hives, periodic fever, bone pain, joint pain, weight loss, malaise, fatigue, swollen lymph gland, enlarged spleen and liver
• Muckle Wells syndrome: periodic episodes of skin rash, fever, joint pain, progressive hearing loss, kidney damage, triggered by cold, heat, fatigue, other stress |
| What are clinical types of urticaria? | • Acute urticaria (less then 6 weeks)
• Episodic urticaria (intermittent attacks of urticaria few to several weeks)
• Chronic urticaria (more than to 6 weeks)
Generalized ordinary urticaria (hives) presents with spontaneous wheals anywhere on the body.
Ordinary urticaria is also known as spontaneous urticaria or idiopathic urticaria
Urticaria may not be present all the time. Some find it more noticeable at certain times of day, or when they are warm or emotionally upset |
| What are etiologies for urticaria? | • Acute urticaria is sometimes due to allergy. Allergy depends on previous exposure to the material, and the development of an immune reaction to it
• IgE is involved, which attaches itself to a receptor on the mast cell and causes it to release its chemical mediators
Causes of acute allergic urticaria
• Drug eruption: most often an antibiotic, but many other drugs have been reported as well as vaccines
• Food allergy: tiny amounts of fish, eggs, nuts and kiwifruit (many others have been reported less often)
• Bee or wasp stings
• While most allergies involve ingestion, injection or inhalation of the allergen, sometimes allergic urticaria can result from skin or mucosal contact with an allergen (rubber, latex) |
| How is acute urticaria in children? | • Acute urticaria remains the most common clinical presentation
• Viral infection in most cases with an evident trigger
• Elucidation of an autoimmune basis in children with CSU
• Investigations should be guided by history |
| What are medications inducing urticaria? | • Penicillin and related antibiotics are common via the IgE-mediatedmechanism
• Aspirin is a common cause of non IgE-mediated mechanism
• 30% of chronic urticaria are exacerbated by aspirin/NSAID use |
| How are severe allergic reactions in urticaria? | • Most allergies are mild, but very allergic individuals may develop serious anaphylactic shock within a few minutes of exposure
• The most frequent causes are:
-antibiotic injections
-bee stings
-ingestion of peanuts
Anaphylaxis results in urticaria, a tight chest, wheezing, faintness and collapse. Medical attention must be sought urgently. A subcutaneous adrenaline (epinephrine) injection will usually be given. Those prone to anaphylaxis should carry an emergency supply (e.g. an EpiPen™) |
| What are non-allergic causes of urticaria? | • Infections: sinusitis, Helicobacter (a cause of stomach ulcers), dental abscess, viral hepatitis, mycoplasma penumonia, infectious mononuclosisand candida
• Serum sickness, due to blood transfusion, viral infection or medicines (e.g. Ceclor™); urticaria is accompanied by fever, swollen lymph glands, painful joints and nausea. It is thought to result from immune complexes of the allergen and antibodies lodging in small blood vessels
• Non-allergic release of mast-cell granules by medicines, especially morphine, codeine, other opiates, and radiocontrast agents. Urticaria provoked by aspirin and other NSAID’s usually involves leukotriene formation, although allergy involving IgE antibodies may also occur with aspirin
• Non-allergic food reactions, from salicylates in fruit, azo dye food colouringagents, benzoate preservatives and other food additives, or from histamine due to bacterial decomposition e.g. scombroid fish poisoning |
| What are causes of chronic urticaria? | • Chronic urticaria (CU) affects 0.5–1% of the general population worldwide with CSU accounting for more than two-thirds of CU cases
• Autoimmune disease and may be associated with other autoimmune conditions such as thyroid disease and coeliac disease Circulating 'anti-idiotypic’ antibodies can be detected in 10% of patients with chronic urticaria. These activate IgE bound on mast cells to cause excessive release of chemicals
• In most cases, chronic urticaria clears up, but 15% still have papules at least twice weekly after 2 years |
| How is recurrent angioedema? | • Without urticaria may be due to C1 esterase deficiency
(protease inhibitor of the complement system)
• There is often a family history of similar problems.
• It may also be caused by angiotensin converting enzyme (ACE) inhibitors such as captopril, quinapril, enalapril and others, which are used to treat heart failure and hypertension. These drugs inhibit kinin breakdown
• Angioedema may also be idiopathic |
| How is urticarial vasculitis? | Urticaria should be distinguished from urticarial vasculitis, in which wheals persist for longer than 24 hours and vasculitis is found on skin biopsy and DIF
It results from immune complex deposition |
| What is physical urticaria? | Urticaria induced by physical influences, take 5 mins to develop lasts 15-30 mins
Cause unknown, dermographism [skin stroking], cholinergic [sweating], cold urticaria [affects skin warming up in reductions of temperature, advise to not subject to wind and swim alone]
Contact urticaria [absorption of substance, allergic or not, papules in area [IgE Abs react to chemicals flour, cosmetics, textiles, latex, rubber, saliva, meat, fish and vegetables cause contact urticaria, dexa, salic, balsam of peru
localized heat urticaria, aquagenic, solar, vibratory, delayed pressure (less common) |
| What are key symptoms of chronic spontaenous urticaria? | • Urticaria is a condition of development of wheals (hives), angioedema or both
• In most cases, CSU is probably an autoimmune disease
• Typical feature of wheal in urticaria patient
• Angioedema in urticaria patient
Typical wheal feature (central swelling surrounded by erythema, prominent itch, occasional burning, Hives last 4-24 hrs while inducible ones last less 30mn to 2 hrs)
Angioedema in urticaria pt (Up to 40%, rapidly developing skin swelling or mucus membrane at level of deep dermis/SC, reabsorbs slowly lasts 2-4 days, sometimes pain and not itch |
| How is dx of CSU? | Hx (shape, size of wheals, onset, associated sx, fam hx, pervious therapies)
PE (assess activity, impact, control and exclude differentials)
Screening (strongly advised, CBC, ESP, CRP)
Medication hx (ACE inhibitors [induce angioedema repalce w/ARBs], hives duration, exacerbations after intake of NSAIDs |
| How is burden of CSU? | . |
| What are pt reported outcome instruments? | UAS7:
• The Urticaria Activity Score summed over 7 days (UAS7) assesses the itch severity (pruritus) and hive count in chronic spontaneous urticaria )CSU) using once- or twice-daily diary-based documentation
• The once- and twice-daily UAS7 scores were highly consistent, supporting the use of either version when evaluating CSU activity and yielded very similar results
DLQI:
• The DLQI consists of 10 questions concerning patients' perception of the impact of skin diseases on different aspects of their health-related quality of life over the last week |
| What are investigations done for urticaria? | • In most cases of urticaria, there is no need for specific
investigations. However, the following tests may be helpful in some cases:
• Full blood count to identify eosinophilia caused by allergy or parasitic infestation, and low WBC from systemic lupus erythematosus
• Thyroid antibodies and function in chronic urticaria
• Complement tests in case of angioedema without urticaria or urticarial vasculitis
• Skin biopsy if wheals are prolonged, to identify vasculitis |
| What are thyroid disorders in urticaria? | Hashimoto (hypothyroid, anti-TPO, to know for sure address and treat it, manage expectations regarding tx responses to antihistamines and omalizumab, counsel pts regarding disease duration and severity. |
| What are urticaria tx goals and approach? | treat disease until its gone, avoid delays to minimize risk factors, go through algorithm |
| What are tx strategies to avoid? | old sedating antihistamines, higher than 4-fold doses of 2nd gen, avoid long term use of corticosteroids, in acute exacerbation short course of glucocorticoids considered.
• Stop the medications to avoid
• Minimize or avoid use of aspirin and codeine. It is usually safe to take paracetamol to relieve pain. NSAID’s should be avoided in those that react adversely to aspirin. ACE inhibitors should be avoided in those with angioedema
• Dietary changes may help. Some urticaria are aggravated by salicylates in certain fruits, or additives including amines, tartrazine)102), benzoates (210-220) and other food chemicals
• Avoid alcohol (it causes vasodilation). Try not to overheat. Cool the affected area with a fan, cold flannel, ice pack or soothing moisturizing lotion |
