Hypochondriasis

Disease Description (Causes and Symptoms)

• Definition: Pruritus is an unpleasant sensation that creates the urge to scratch the skin and is a symptom that occurs in many skin diseases and systemic diseases.
• Main causes
  • Skin diseases: atopic dermatitis, contact dermatitis, urticaria, scabies, lichen simplex chronicus, insect bites, nummular eczema, etc.
  • Systemic diseases: chronic kidney disease (uremic pruritus), cholestasis (such as primary biliary cholangitis and biliary obstruction), hyperthyroidism/hypothyroidism, diabetes mellitus, lymphoma/leukemia, HIV, etc.
  • Drug-related (drug-induced), psychological factors (stress, neurogenic factors)
  • Environment/dry skin: irritating fabrics (such as wool), low humidity, frequent hot baths
• Pathophysiology (brief): Pruritic signals are transmitted through peripheral sensory nerves (C fibers) in the skin and pathways in the central nervous system. In addition to histamine, various mediators (interleukins, proteases, bile acids, opioids, etc.) are involved. When the condition becomes chronic, central and peripheral sensitization may progress, creating a vicious cycle.
• Symptoms: Localized or generalized itching, abrasions/bleeding/infection caused by scratching, skin thickening (lichenification), sleep disturbances and psychological distress

Treatment Methods

• Basic principles: Identify and treat the underlying possible cause (e.g., correcting cholestasis, managing kidney failure) → symptom-relief treatment when treating the cause is not possible or as an adjunct
• Topical treatment
  • Moisturizers (fragrance-free·emollients) — apply immediately after bathing
  • Skin-cooling preparations: calamine lotion, lotion containing 1% menthol
  • Topical steroids: use for a short period depending on the inflammatory skin disease
  • Topical capsaicin (partially effective for localized neurogenic pruritus), topical doxepin cream (caution: absorption and adverse effects)
  • Cold compresses·rubbing (as alternatives to scratching)
• Systemic medications
  • Antihistamines: used for allergies/acute pruritus or as a sleep aid (sedating types). Their effectiveness is limited in chronic nonhistaminergic pruritus.
  • Neuromodulators: gabapentin, pregabalin (effective for uremic·neurogenic pruritus)
  • Antidepressants: mirtazapine (nocturnal pruritus), SSRIs (e.g., sertraline — used for pruritus caused by certain conditions)
  • Cholestyramine, rifaximin (Xifaxan?) no — medications such as cholestyramine·rifampicin (rifampin), not cholestyramine·rifaximin: cholestyramine (bile acid excretion), rifampicin, and naltrexone (an opioid antagonist) may be considered for cholestatic pruritus
  • Opioid antagonists (e.g., naltrexone): used for some cases of refractory generalized pruritus
• Phototherapy: Narrowband UVB is effective for chronic pruritus
• Procedures·surgery: Surgical and medical treatment for the underlying disease (such as cholestasis caused by biliary obstruction) should follow the guidelines for that disease
• Lifestyle management (important)
  • Prevent dry skin: bathe in lukewarm water, do not scrub the skin, moisturize immediately after bathing
  • Avoid irritants: avoid wool·irritating clothing, refrain from using strong soaps·detergents
  • Manage temperature·humidity: avoid overheating·sweating, maintain appropriate indoor humidity
  • Prevent self-injury (scratching): keep fingernails short and use alternative behaviors (rubbing, applying compresses)
  • Limit triggers such as caffeine·alcohol·cola
• Precautions and medication-related considerations
  • Sedating antihistamines: beware of drowsiness; do not drive or operate machinery
  • Rifampicin and other hepatic enzyme inducers may cause drug interactions and affect liver function — liver function tests are necessary
  • Discuss the adverse effects and indications of phototherapy·systemic medications with a specialist
• Risk of complications
  • Secondary bacterial infection, skin pigmentation·scarring, lichenification, sleep disturbances·depression·reduced quality of life

Outpatient Visit Checkpoints (Preparation Items and Example Questions)

• Items/preparations
  • List of currently taken medications·supplements (if possible, photos or medication packaging)
  • Past medical history (kidney·liver·thyroid diseases, history of cancer, etc.)
  • Recent test results (blood tests, liver function·kidney function·thyroid tests, etc.), if available, printed or saved as a file
  • Record the time the itching began, its progression, aggravating/improving factors (time of day·food·medications·clothing·temperature, etc.)
  • Photos of itchy areas (especially when skin lesions are present)
  • Impact on sleep·daily life (e.g., number of nighttime awakenings, limitations on daily activities)
• Key points to tell the doctor during the outpatient visit (examples)
  • Distribution of itching: localized (e.g., hands·feet) vs. generalized
  • Time pattern of itching: Is it worse at night?
  • Temporal relationship with medication use (newly started medications)
  • Whether systemic symptoms are present: weight loss, fever, jaundice, enlarged lymph nodes

General Example Questions to Ask the Doctor

• "What are the possible causes of this itching? What additional tests do you recommend?"
• "What initial tests do you recommend (blood tests·liver·kidney·thyroid, etc.), and what will the next step be depending on the results?"
• "Could any of the medications I am taking (list) be causing the itching? Should I stop taking them?"
• "What are the main adverse effects of the medication you prescribe, and if it is not effective, what are the next options?"
• "What self-care methods can I practice immediately in my lifestyle, and what behaviors should I avoid?"

Examples of Condition-Specific Questions

• "The itching is generalized and there are almost no skin lesions (idiopathic generalized pruritus). Which systemic tests (liver·kidney·thyroid·tumor markers, etc.) do you recommend prioritizing?"
• "My sleep is affected by itching that is especially severe at night. What medications or nonmedication treatments (phototherapy, medication selection) are recommended to improve sleep?"

(Note: The information above is general medical information. Diagnosis and treatment plans based on an individual's condition should be determined in consultation with the treating specialist.)