Fever of unknown origin

Disease Description (Causes and Symptoms)

• Name: Taeyeol (symptoms consistent with infantile atopic dermatitis) — eczematous dermatitis findings commonly occurring in infants within the first few months after birth
• Causes and pathophysiology: Develops through the combined effects of genetic predisposition (e.g., defects in skin-barrier proteins such as filaggrin), immunological bias (Th2 predominance), impaired skin barrier function, and environmental irritants (dryness, temperature, sweat, detergents, etc.).
• Main symptoms: Dryness, redness, small papules and blisters, crusting, and severe itching mainly on the face and in areas such as the cheeks, forehead, behind the ears, neck, groin, and inner thighs (in infants, sleep disturbance and skin damage caused by scratching may occur).

Treatment Methods

• General principles: Skin moisturization and avoidance of irritants are the foundations of treatment. Stepwise treatment is applied according to the symptoms and severity.
• Skin care (daily care)
  • Manage indoor temperature and humidity (humidity of approximately 50–60% is recommended).
  • Wear minimally irritating cotton clothing and avoid excessive sweating.
  • Use lukewarm water (approximately 25°C) and limit bathing to 5–10 minutes. Apply sufficient moisturizer (lotion, cream, or oil) within 3 minutes after bathing.
  • Keep the nails short and use mittens if necessary.
  • Avoid strongly scented soaps, detergents, fabric softeners, rough sponges, and similar products.
• Moisturizers: Use fragrance-free, low-irritant emollients frequently (several times a day).
• Topical medications
  • Use low-potency topical corticosteroids (e.g., hydrocortisone 1%) for a short period to control inflammation. Follow pediatric medication and usage instructions.
  • If necessary, adjust the potency stepwise according to the instructions of a dermatologist.
  • Topical calcineurin inhibitors (e.g., pimecrolimus) may be used in some age groups and situations, but specialist judgment is required based on age, indication, and safety.
• Systemic medications
  • In cases of severe itching or severe sleep disturbance, antihistamines may be used for a short period (those that mainly cause drowsiness are used primarily as sleep aids); for severe systemic inflammation, immunomodulators may be considered under specialist supervision (rare in infants).
• Infection management: If the skin is infected with secondary bacteria (mainly Staphylococcus aureus) or viruses, appropriate topical or systemic antibiotic/antiviral treatment is necessary.
• Other treatments: Phototherapy is mainly used in older children and adults and is limited in infants.
• Precautions
  • Long-term or extensive use of high-potency topical steroids may pose risks of impaired growth and skin atrophy; follow specialist instructions.
  • Arbitrary food restriction is not recommended. If a food allergy is suspected, consult a specialist before undergoing testing.
  • If adverse reactions (severe rash, difficulty breathing, pain, etc.) occur while using medication, stop immediately and seek medical attention.

Checklist Before an Outpatient Visit (Including Items to Bring and Example Questions)

• Recommended items to bring
  • A list of currently used medications and prescriptions (including topical products), or photos of the medication products
  • Recent photos showing the skin findings (at the onset and when symptoms were at their worst)
  • A record of the symptom onset date and progression (aggravating factors, seasonal, dietary, or lifestyle changes, etc.)
  • Previous relevant test results, if any, and family history (atopic conditions, asthma, allergies, etc.)
• Key information to provide to the doctor during the outpatient visit
  • When and where the symptoms began, and factors that worsen them (sweat, food, detergents, etc.)
  • Treatment attempts (medications, moisturizers, bathing habits, etc.) and their effects
  • Whether systemic problems such as sleep disturbance, feeding problems, or inadequate weight gain are present
• Example questions (questions a patient may ask during an outpatient visit)
  • What are the expected effects and side effects of this medication?
  • Which moisturizer should be used, and how often should it be applied?
  • If the symptoms are not well controlled, what is the next step in treatment?

Examples of Disease-Specific Questions to Ask the Doctor

• Is it necessary to evaluate whether these symptoms are caused by a specific food (e.g., milk or eggs)? (If so, what tests should be performed, and when?)
• How long and at what potency should topical steroids be used? What precautions can reduce side effects?

(Note: If emergency symptoms—difficulty breathing, rapidly developing swelling of the face, lips, or throat, systemic fever, pallor, lethargy, etc.—occur, go to the emergency room immediately.)

Brief prognosis summary: With appropriate skin care and treatment, many infants improve, but some may continue to have an atopic tendency after childhood.