About Itchy Skin (Pruritus)
Itching is one of the most common dermatological complaints and a bothersome symptom that can significantly diminish quality of life. The causes are not only superficial, such as dry skin, allergies, or insect bites, but also frequently include underlying medical conditions like liver disease, kidney disease, diabetes, or thyroid disorders.
Since our clinic has both internal medicine and dermatology departments, we can simultaneously treat the skin condition and investigate systemic diseases, thereby identifying the true cause of the itching.
"Itchy skin with no visible rash" warrants attention
If you experience whole-body itching without any visible rash or redness, there is a possibility that a systemic disease is hidden. Especially if you have whole-body itching at night, jaundice, or weight loss, we strongly recommend an internal medicine consultation.
Classification of Itching
Classification by Cause
| Classification | Main Causes |
|---|---|
| Cutaneous Pruritus | Eczema, atopic dermatitis, hives, dryness, insect bites, tinea |
| Systemic Pruritus | Liver disease, kidney disease, blood disorders, endocrine disorders, malignant tumors |
| Neuropathic Pruritus | Neuropathy, postherpetic neuralgia, psychogenic factors |
| Drug-Induced Pruritus | Caused by medications such as antibiotics, antihypertensives, opioids |
Classification by Distribution
- Localized: Itching in only one area (insect bites, contact dermatitis, tinea, postherpetic neuralgia)
- Generalized: Whole-body itching (dryness, internal medical conditions, drug-induced, scabies)
Common Skin Conditions Causing Itching
| Condition | Characteristics | Main Treatments |
|---|---|---|
| Atopic Dermatitis | Symmetrical, often on flexural surfaces, chronic course | Moisturizers, topical steroids, tacrolimus, novel drugs |
| Hives (Urticaria) | Wheals, disappear within hours | Oral antihistamines |
| Contact Dermatitis | Redness and blisters corresponding to the causative substance | Removal of cause, topical steroids |
| Seborrheic Dermatitis | Redness and dandruff on scalp, eyebrows, sides of nose | Topical antifungals, mild steroids |
| Asteatotic Eczema (Xerosis Cutis) | Worsens in winter, lower legs, flaky skin | Mainly moisturizers |
| Tinea (Athlete's Foot) | Between toes, hyperkeratosis, confirmed by KOH test | Topical antifungals, oral medication |
| Scabies | Severe itching at night, linear lesions between fingers | Oral ivermectin, topical phenothrin |
| Prurigo | Hard, raised, intensely itchy lesions | Topical steroids, oral medication |
Systemic Diseases (Internal Medical Causes) That Should Not Be Overlooked
Persistent generalized itching without a visible rash can sometimes indicate an underlying internal medical condition.
| Condition | Characteristics of Itching | Confirmatory Tests |
|---|---|---|
| Liver and Biliary Tract Disease (Cholestasis) | Generalized itching, jaundice | Liver function tests, biliary enzymes (ALP, γGTP, bilirubin) |
| Chronic Kidney Disease (Uremic Pruritus) | Common in dialysis patients, generalized | Kidney function (Cr, eGFR, BUN) |
| Diabetes | Itching due to dryness and neuropathy | Blood glucose, HbA1c |
| Thyroid Disorders | Hyperthyroidism causes itching/sweating, hypothyroidism causes dryness | TSH, FT4 |
| Iron Deficiency Anemia | Dryness, itching, restless legs | Complete blood count, ferritin |
| Polycythemia Vera | Itching after bathing (aquagenic pruritus) | Complete blood count (red blood cells, Hb) |
| Malignant Tumors (Lymphoma, Cancer) | Intractable generalized itching, weight loss | Full body examination |
| HIV, Viral Infections | Chronic itching, rash | Medical history, tests as needed |
| Drug-Induced | Associated with newly started medications | Medication history |
If you have these symptoms, be sure to see an internal medicine doctor.
Itching accompanied by jaundice (yellow skin/whites of eyes), significant weight loss, night sweats, fever, or swollen lymph nodes may indicate a serious underlying condition. Do not neglect these symptoms; seek medical attention promptly.
About Atopic Dermatitis
Atopic dermatitis is a chronic inflammatory skin disease caused by a combination of impaired skin barrier function and an overactive immune response. The prevalence in Japan is reported to be 10-20% in children and 1-3% in adults.
Characteristics of Atopic Dermatitis
- Accompanied by intense itching
- Symmetrical eczema, often on flexural surfaces (inner elbows, behind knees, neck)
- Chronic course (over 6 months) with repeated remission and exacerbation
- Family history of atopic diathesis (asthma, hay fever, food allergies)
Pillars of Treatment
| Treatment | Role |
|---|---|
| Moisturizers (heparin analogues, etc.) | Improve barrier function, fundamental to all treatment |
| Topical Steroids | Suppress inflammation, available in various strengths |
| Tacrolimus Ointment (Protopic) | For face, neck, and areas with risk of skin atrophy |
| Delgocitinib Ointment (Corectim) | New topical JAK inhibitor, non-steroidal |
| Difamilast Ointment (Moizert) | New topical PDE4 inhibitor |
| Oral Antihistamines | Reduce itching |
| Dupilumab (Dupixent) Injection | Biologic for moderate to severe cases (twice a month) |
| JAK Inhibitors (Oral: Rinvoq, Olumiant, Cibinqo) | For severe intractable cases, requires collaboration with specialists |
Concerns about steroids
If you avoid steroids due to fear and discontinue treatment, symptoms may worsen and become chronic. When used correctly (appropriate strength for the necessary duration), it is known that long-term side effects are unlikely. Please do not hesitate to consult us if you have any concerns.
Dryness-Induced Itching (Asteatotic Eczema, Xerosis Cutis)
This condition occurs when the skin's barrier function is compromised due to aging or winter dryness, leading to itching even from mild stimuli. It is particularly common in elderly individuals and on the lower limbs.
Characteristics
- Worsens in winter and dry seasons
- Common on lower legs and forearms (areas with fewer sebaceous glands)
- White, flaky skin that appears powdery
- Aggravated by hot baths and heating
Measures
- Apply moisturizers (heparin analogues, petroleum jelly, urea cream) at least twice a day
- Bathe in lukewarm water (38-40℃) for a short duration (within 10-15 minutes)
- Avoid excessive use of soap/body wash (wash only specific areas)
- Apply moisturizer within 3 minutes after bathing (the "golden time")
- Maintain indoor humidity at 50-60% with a humidifier
- Avoid wool and synthetic underwear; choose cotton or silk
Lifestyle Tips to Relieve Itching
To Prevent Itching from Worsening
- Do not scratch (scratching releases more histamine, making itching worse)
- Keep nails short, wear cotton gloves at night
- Cool the area (wrap an ice pack in a towel and apply)
- Take lukewarm baths (hot water exacerbates itching)
- Limit alcohol, spices, and caffeine
- Manage stress and get enough sleep
- Maintain appropriate indoor humidity and temperature
Things to Avoid
- Harsh soaps and body washes
- Hot water, long baths
- Direct contact with wool or synthetic materials
- Excessive use of fabric softener
- Scratching or rubbing vigorously
- Long-term self-medication with over-the-counter products
Examination and Tests at Our Clinic
Key Points for Medical History Taking
- Location and distribution of itching (localized vs. generalized)
- Onset, duration, and daily fluctuations
- Relationship with seasonality and temperature changes
- Living environment (clothing, detergents, pets, new construction)
- Diet, stress, sleep
- Past medical history, current medications
- Family history of atopy/allergies
- Accompanying symptoms (jaundice, weight loss, fatigue)
Tests at Our Clinic
| Test | Purpose |
|---|---|
| Blood tests (CBC, liver/kidney function, thyroid, blood glucose) | Exclusion of systemic diseases |
| Allergy tests (IgE, View39) | Identification of allergens |
| KOH Direct Microscopy | Confirmation of tinea |
| Skin inspection and dermoscopy evaluation | Type of eczema, burrow signs in scabies |
| Inflammatory markers (CRP) | Assessment of infection/inflammation |
Referrals as Needed
- Severe atopic dermatitis (specialized medical institutions for dupixent/JAK inhibitors)
- Intractable psoriasis (biologic agents)
- Suspected malignant tumors (oncology/surgery)
- Endoscopy (gastrointestinal diseases)
Characteristics of Our Itching Treatment
- Evaluate the cause of itching from both dermatological and internal medicine perspectives
- Immediate screening for systemic diseases with blood tests (liver, kidney, thyroid, blood glucose)
- Offers allergy tests (including View39)
- Treats atopic dermatitis with moisturizers, steroids, tacrolimus, and new drugs
- Selects and prescribes appropriate moisturizers for dry skin
- Refers severe cases to institutions specializing in biologic agent initiation
- Reviews and adjusts medications for suspected drug-induced itching
- No appointment necessary, walk-ins welcome / Open daily 9 AM - 9 PM / 1 minute walk from Jujo Station
Do not neglect persistent itching
Itching significantly reduces quality of life and affects sleep, concentration, and mood. Many people can improve with proper diagnosis and treatment. Do not endure it; please consult us first.
