Chronic spontaneous urticaria

Chronic spontaneous urticaria
Other names	Chronic idiopathic urticaria, CIU, and CSU.[1]
Typical presentation of chronic spontaneous urticaria.
Specialty	Dermatology
Symptoms	Urticaria, angioedema, headache, fatigue, joint pain or swelling, gastrointestinal symptoms flushing, wheezing, and palpitations.[2]
Usual onset	typically 30s-50s[2]
Duration	Episodic.[2]
Causes	NSAIDs, heat, tight clothing or straps, stress, variations in diet, and alcohol.[2]
Risk factors	Allergic diseases, autoimmune conditions, and thyroid disorders.[2]
Diagnostic method	Clinical findings, complete blood count with differential, CRP or ESR, and skin biopsy.[2]
Differential diagnosis	Urticarial vasculitis, lupus, cryoglobulinemia, Schnitzler syndrome, mast cell disorders, polymorphic eruption of pregnancy, hypereosinophilic syndrome, and Cryopyrin-associated periodic syndromes.[2]
Treatment	Avoidance of exacerbating factors, and antihistamines.[3]
Medication	Cetirizine, Levocetirizine, Fexofenadine, Loratadine, and Desloratadine.[3]
Prognosis	Spontaneous remission in 30-50% of cases.[2]
Frequency	1% of the general population in the United States.[2]

Chronic spontaneous urticaria (CSU) also known as Chronic idiopathic urticaria (CIU) is defined by the presence of wheals, angioedema, or both for more than six weeks. The most common symptoms of chronic spontaneous urticaria are angioedema and hives that are accompanied by itchiness.

Chronic spontaneous urticaria, despite its cause being unknown, is linked to a higher prevalence of autoimmune diseases, and is often worsened by triggers like stress, infections, certain foods, or nonsteroidal anti-inflammatory drugs. The hives and angioedema seen in CSU is thought to be linked to the degranulation of skin mast cells. Mast cells release proteases, histamine, cytokines, and arachidonic acid metabolites, causing swelling, redness, and itching.

The standard workup for CSU differs in different parts of the world. However, most doctors agree on the importance of having a detailed history. The main goal is to identify any urticaria-inducing factors because eliminating them is the most straightforward course of treatment. Basic laboratory tests, such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and possibly a complete blood count (CBC) with differential, are critical for detecting signs of systemic inflammation and ruling out autoinflammatory conditions as well as urticarial vasculitis with systemic involvement.

For the treatment of chronic spontaneous urticaria, a two-pronged strategy has been proposed. The underlying cause(s) and/or eliciting trigger(s) must first be identified and eliminated. The second approach is pharmacotherapy, which aims to alleviate symptoms. A therapeutic approach should be implemented in three steps, according to current guidelines: (1) taking a second-generation antihistamine once daily; (2) increasing the second-generation antihistamine's daily dose up to four times; and (3) pursuing off-label therapy with cyclosporine A or montelukast or add-on therapy with omalizumab, which is an approved treatment option for CSU.^[4]