Types of skin allergies
Urticaria (hives): Raised, itchy welts (wheals) that can appear anywhere on the body and typically resolve within 24 hours, though new ones may appear. Acute urticaria lasts less than 6 weeks; chronic urticaria lasts more than 6 weeks. Triggers include foods (shellfish, nuts, eggs), medications (NSAIDs, antibiotics), infections, and physical factors (cold, pressure, exercise). In many cases of chronic urticaria, no trigger is identified. Angioedema is a deeper swelling that often accompanies urticaria, commonly affecting lips, eyelids, and tongue.
Atopic dermatitis (eczema): Chronic, recurring inflammatory skin condition characterized by dry, itchy, red patches. Common in children but persists into adulthood. Associated with asthma and allergic rhinitis (the "atopic triad"). Triggered by dry skin, heat, sweating, wool, soaps, and stress. Contact dermatitis: Reaction at the point of contact with a trigger. Allergic contact dermatitis (e.g., to nickel in jewelry, latex, fragrances, hair dye) develops over 24–48 hours after exposure. Irritant contact dermatitis (detergents, bleach, prolonged water exposure) is more immediate. Drug reactions: maculopapular rash appearing days after starting a new medication is the most common pattern.
Key facts
- ✓In Peru, common triggers include dust mites, pets, nickel in jewelry, fragrances, latex, and certain medications
- ✓Distinguishing allergy from irritation requires a doctor — they have different causes and treatments
- ✓Oral antihistamines (cetirizine, loratadine) are first-line for urticaria — sedating types help at night
- ✓Topical corticosteroids are effective for eczema and contact dermatitis but should not be used long-term on the face
- ✓Go to the ER immediately if swelling affects the throat, breathing is difficult, or there is dizziness — signs of anaphylaxis
Get your skin allergy evaluated online
A physician can review photos and symptoms to diagnose the type of reaction and prescribe the right treatment — from S/80.
Book consultation →Treatment options
Antihistamines: Second-generation non-sedating antihistamines (cetirizine 10 mg, loratadine 10 mg, fexofenadine 180 mg) are first-line for urticaria and taken daily in chronic cases. First-generation sedating antihistamines (chlorphenamine) can be used at bedtime when itching disrupts sleep. In chronic urticaria, high-dose second-generation antihistamines (up to 4x standard dose) are used before escalating to other treatments. Topical corticosteroids: Mild (hydrocortisone 1%) for the face and skin folds; moderate to potent (betamethasone, clobetasol) for thicker skin or resistant areas. Use for short courses (1–2 weeks) to control flares in atopic dermatitis.
Emollients: Essential in atopic dermatitis — applied generously and frequently to restore the skin barrier (urea-based creams, ceramide moisturizers). Oral corticosteroids (prednisone) for severe acute reactions: short course only, not for chronic management. Systemic treatment for severe chronic urticaria or eczema: omalizumab (anti-IgE) or dupilumab (anti-IL-4/13) are advanced options available through dermatology. Trigger avoidance remains central to all treatments — identifying and eliminating the cause is more effective than any medication.
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Online medical consultation from S/80. Available across all of Peru.
Book nowWhen to go to the ER: anaphylaxis warning signs
Go to the emergency room immediately if any of these signs appear: throat swelling, hoarse voice, or difficulty swallowing; difficulty breathing or wheezing; dizziness, lightheadedness, or loss of consciousness; widespread hives developing rapidly (within minutes) combined with any of the above. These are signs of anaphylaxis, a life-threatening systemic allergic reaction. If you have a known history of severe allergy, carry an epinephrine auto-injector (EpiPen) and use it immediately while calling emergency services.
FAQ
How do I know if it's an allergy or just irritation?
Allergic reactions involve the immune system — they require prior sensitization and improve with antihistamines. Irritant reactions are direct tissue damage from chemicals (bleach, harsh soaps) and don't respond to antihistamines. The pattern, location, and history of trigger exposure help differentiate them. A physician can clarify based on the presentation.
I have chronic hives — can they be cured?
Chronic spontaneous urticaria often resolves spontaneously within 1–5 years. While active, it's managed with daily antihistamines and, in resistant cases, omalizumab injections (highly effective in >70% of patients). Identifying and eliminating any trigger — though one is often not found — is important. An allergist evaluation is recommended for chronic cases.
Can a skin allergy be evaluated online without seeing the rash in person?
Yes, in most cases. Upload clear photos of the affected skin during the online consultation. A physician can identify the likely type of reaction (urticaria, eczema, contact dermatitis, drug rash) and prescribe appropriate treatment based on photos plus symptom description. If needed, they'll refer you to a dermatologist for in-person evaluation.
Is skin allergy testing available in Peru?
Yes. Allergist-performed skin prick testing (for IgE-mediated allergies: foods, pollens, dust mites, animal dander) and patch testing (for contact allergies to metals, fragrances, preservatives) are available at private allergy clinics in Lima. An online general physician can refer you and help determine whether this evaluation is needed for your case.
Conclusion
Most skin allergies are manageable with the right treatment and trigger identification. A physician evaluation — even online — establishes the correct diagnosis and prevents months of trial and error with over-the-counter products.
At Delvir, you can consult a physician online from S/80, from anywhere in Peru.