Metachromatic leukodystrophy

1) Disease Description (Causes and Pathophysiology · Main Symptoms)

• Summary of definition: Allergic rhinitis is a disease in which repeated IgE-mediated hypersensitivity reactions (type I) to specific antigens (house dust mites, pollen, pet dander, cockroaches, etc.) occur in the nasal mucosa, causing sneezing, itching, clear runny nose, nasal congestion, and other symptoms.
• Pathophysiology: Antigen exposure → activation of mast cells in the nasal mucosa → release of mediators such as histamine and leukotrienes (early-phase response) → persistent inflammation due to infiltration of inflammatory cells (such as eosinophils) (late-phase response) → vasodilation and increased permeability causing edema (nasal congestion), increased secretion (runny nose), and sneezing and itching due to nerve stimulation.
• Main symptoms: Sneezing, frequent watery runny nose, itching of the nose/palate/throat/eyes, nasal congestion (nasal obstruction), reduced sense of smell, eye redness and tearing (allergic conjunctivitis when accompanying), sleep disturbance, and fatigue. Symptoms may be seasonal (pollen) or perennial (house dust mites, etc.).

2) Treatment Methods and Precautions

• Basic principles: Avoid possible causative allergens → medication to relieve symptoms → immunotherapy or surgical treatment if necessary
• Avoidance therapy (lifestyle management)
  • House dust mites: Maintain indoor humidity at 50% or lower, use bedding covers (allergen-proof covers), wash blankets and bedding at 60℃ or higher once a week, reduce carpets and fabric sofas, and use a vacuum cleaner with a HEPA filter or clean with a wet mop.
  • Pets: Minimize contact or prohibit indoor access (when possible), and clean frequently.
  • Pollen: Avoid going outdoors on days with high pollen levels, shake out clothes and shower after returning home, and reduce morning activities.
  • Cockroaches: Maintain cleanliness and perform pest control.
• Medication (standard)
  • Intranasal corticosteroids (topical nasal sprays): First-line treatment for moderate or more severe symptoms (improves nasal itching, sneezing, runny nose, and nasal congestion). It takes several days to 1–2 weeks for effects to appear. Maintain with the lowest dose.
  • Second-generation oral antihistamines (cetirizine, loratadine, fexofenadine, etc.): Effective for sneezing, itching, and runny nose; products that cause less drowsiness are preferred.
  • Intranasal antihistamines (azelastine, etc.): Rapid symptom relief (runny nose and sneezing).
  • Leukotriene receptor antagonists (montelukast): Consider when asthma or nasal polyps are also present.
  • Nasal decongestants (topical sprays and oral medications): Used for nasal congestion for a short period (usually topical agents for no more than 3–7 days); beware of recurrence (rhinitis medicamentosa) with long-term use.
  • Intranasal anticholinergics (ipratropium spray): Mainly useful for copious watery nasal discharge.
• Immunotherapy
  • Consider for patients with confirmed sensitization to specific IgE (skin testing and specific IgE testing are required). Subcutaneous (SCIT) or sublingual (SLIT) immunotherapy is available, and generally continuing treatment for 3–5 years may produce a long-term tolerance effect. It is performed under the guidance of an allergist.
• Biologic therapy
  • In severe cases or when accompanied by asthma or polyps, anti-IgE agents (omalizumab), etc., may be options; however, indications for allergic rhinitis alone are limited. Consultation with a specialist is necessary.
• Surgical treatment
  • If unresponsive to medication (such as chronically hypertrophied inferior turbinates), turbinate reduction may be considered; corrective surgery may be considered for structural problems (such as deviated nasal septum).
• Precautions
  • Avoid long-term use of topical nasal decongestants (recurrent nasal congestion).
  • When using corticosteroids for a long period in children, consider effects on growth, use the minimum effective dose, and monitor.
  • Consult a specialist regarding medication use during pregnancy or breastfeeding.

3) Outpatient Visit Checkpoints (Items to Bring · Information Helpful During the Consultation)

• Items and documents to bring
  • A list of currently used medications (including prescription and OTC medications), along with doses and medication start dates.
  • Copies of previous test results (skin allergy tests, specific IgE tests, nasal endoscopy, sinus imaging, etc.).
  • Symptom diary (when symptoms occur, whether they are seasonal, time of day, triggering factors, symptom severity/effects on daily life) — record for at least 2 weeks if possible.
  • Information about environments that may trigger allergies (whether there are pets, home layout and presence of carpets, workplace/school environment).
  • Records of previous treatments (medications, immunotherapy, surgery) and their effects and side effects.
• Self-check before the visit (simple questions)
  • Do symptoms occur mainly throughout the year, or are they worse during a particular season?
  • Is nasal congestion the main symptom, or is runny nose the main problem? Do you have sleep problems or fatigue?
  • Do you have a history or family history of asthma or atopic dermatitis?
• Photos to show the doctor during the visit (optional)
  • Photos of the inside of the nose (nasal turbinates) or redness around the eyes (taken with a mobile phone) — for reference if needed.

4) Examples of General Questions to Ask the Doctor

• "What is the most appropriate first-line treatment for my symptoms?"
• "What are the expected effects and side effects of the medication I am going to use (intranasal corticosteroids/antihistamines, etc.)?"
• "How long should I use this medication, and what are the criteria for stopping it?"
• "Are there any interactions with other medications I am currently taking (or with pregnancy or breastfeeding)?"
• "Why do you recommend immunotherapy, and what are the expected benefits, risks, costs, and duration?"
• "How do you decide on the next step when symptoms are not well controlled (surgery, biologics, etc.)?"

5) Examples of Disease-Specific Questions

• "If I test positive for house dust mites (or a specific antigen), what specific environmental measures should I prioritize at home first?"
• "Nasal congestion is my main symptom, but it has not improved much with medication. What are the criteria for considering surgical treatment (such as turbinate reduction)?"

(Note: The information above is educational information compiled based on general medical guidelines and evidence. Individual diagnosis and treatment should be determined based on consultation with a specialist and test results.)