SYMPTOMS

What are the specific manifestations of skin rashes?

A skin rash is a common dermatological lesion that can occur due to various factors such as skin diseases, systemic conditions, medications, food, or infections, leading to surface damage on the skin. Depending on the cause, rashes may present differently.

• Clinically common types of rashes and their specific manifestations include:

1. Macules: Localized skin redness, but black, brown, or white discoloration may also appear, usually without elevation. They are mainly classified into four types: ① erythema; ② petechiae; ③ hyperpigmented macules; ④ hypopigmented macules.
2. Papules: Localized skin redness with raised lesions. Besides red, they may also appear white, black, yellow, or purple.
3. Maculopapular rash: Raised lesions with localized redness, intermediate between macules and papules.
4. Wheals: Slightly elevated, pale or red localized edema on the skin surface.
5. Vesicles: Localized fluid-filled blisters on the skin surface. If the fluid is serous lymph, they are called vesicles; if pus-filled, they are called pustules^[1]. Blood-filled blisters are called hemorrhagic blisters.

• In addition to the above manifestations, some patients may experience swelling, nodules, cysts, erosion, ulcers, pain, or itching. Those with infections may also develop symptoms like fever and fatigue^[2,3].

TREATMENT

What are the ways to treat rashes?

• **Treatment of the primary disease**: If the rash is caused by medication, the drug should be discontinued or the treatment plan adjusted under a doctor's guidance. If it is caused by other chronic conditions, seek timely medical attention at the relevant department and receive active treatment. The rash will alleviate or disappear as the underlying condition improves or resolves.
• **Oral medication**: Depending on the cause, appropriate medications should be selected. Antihistamines are used for allergic conditions, antibiotics for bacterial infections, antiviral drugs for viral infections, and antifungal medications for fungal infections. For example, rashes caused by the herpes zoster virus can be treated with drugs like acyclovir or valacyclovir, which generally have no significant side effects but must be taken under medical supervision. Self-medication should be avoided^[2,3].
• **Topical treatments**: Depending on the condition, various topical medications can be used, including corticosteroids, antibiotics, antifungals, and retinoids, which help with disinfection, antiviral effects, anti-keratinization, and anti-inflammation. Common options include calamine lotion, acyclovir cream, neomycin ointment, terbinafine cream, mometasone furoate cream, and tazarotene ointment^[2,3].

• **Physical therapy**: Localized exposure to ultraviolet or infrared lamps can help alleviate symptoms^[2,3]. Other methods include electrotherapy, cryotherapy, and laser treatment.

How should rash patients care for their skin during the illness?

• Keep the skin clean, bathe regularly, and change clothes and bedding promptly.
• Avoid scratching or excessive washing when the skin is itchy. Apply moisturizers or medicated ointments as directed by a doctor.
• Do not puncture blisters or pustules on the skin to prevent infection.
• Choose breathable, cotton-based clothing and avoid exposing affected skin to irritants like alcohol or soap.
• In summer, take protective measures such as wearing sunscreen, sun-protective clothing, or using an umbrella to avoid sunburn.

What precautions should rash patients take in daily life?

• Maintain a regular sleep schedule, get adequate rest, and avoid overexertion.
• Stay in a positive mood, manage stress through communication with loved ones, exercise, or listening to music, which aids recovery.
• During the illness, reduce intake of fish, shrimp, dairy, and spicy foods, as they may worsen allergic reactions.
• Wear loose, breathable clothing and footwear, and change promptly if they become damp.

For pet owners, ensure regular check-ups for pets. Those allergic to pet fur should avoid contact with animals.

DIAGNOSIS

Under what circumstances should a rash prompt a hospital visit?

• Seek medical attention promptly if a rash appears without a clear cause to determine its origin;
• If the rash recurs repeatedly or persists for an extended period, seek medical care;
• If symptoms like itching or pain are severe, it is advisable to consult a doctor.

Which department should be consulted for a rash?

Dermatology.

How is a rash diagnosed? What tests are needed during the visit?

Doctors will make a comprehensive diagnosis based on the patient's medical history, physical examination, and laboratory test results.

• Medical history: The doctor will inquire about past medical conditions, exposure to food or medications, the duration of the rash, changes in its size or spread, and overall health. Providing accurate information is crucial for diagnosis.
• Physical examination: The doctor will observe, touch, and press the affected area to determine the type of rash.
• Laboratory tests: Further tests may be conducted to confirm the diagnosis. Blood tests can identify bacterial or viral infections or autoimmune diseases. For fungal infections like athlete's foot, skin scrapings may be examined under a microscope. For infectious skin conditions with blisters or pus, fluid samples may be tested. Allergy testing can identify triggers for allergic reactions. In complex cases, a skin biopsy may be required^[1].
• Skin CT: Non-invasive skin imaging is well-tolerated by patients. If other tests are inconclusive, a skin biopsy with pathological examination may be performed for a definitive diagnosis.

POTENTIAL DISEASES

What Causes Rashes?

• Medication factors: Some individuals may be sensitive to antibiotics, antipyretics, analgesics, sedatives, or hypnotics, which can trigger allergic rashes.
• Environmental factors: Workers in chemical plants may experience skin irritation due to prolonged exposure to chemicals; those in landscaping, mountainous areas, or agriculture may develop rashes from insect bites.
• Infectious factors: Bacterial, viral, or fungal infections can lead to rashes on the skin surface.
• Disease factors: Individuals with autoimmune or immunodeficiency disorders (e.g., leukemia, AIDS, cancer) or chronic conditions (e.g., diabetes) have weakened immunity, making them more susceptible to bacterial, fungal, or viral infections.
• Chemical factors: Synthetic fabrics in close-contact clothing or certain ingredients in cosmetics may irritate the skin and cause rashes^[2,3].

What Diseases Might Rashes Be Associated With?

Different types of rashes may be linked to different diseases:

• Macules: These can be erythematous, hemorrhagic, hyperpigmented, or hypopigmented. Erythematous macules may relate to typhus, erysipelas, or erythema multiforme. Hemorrhagic macules are seen in allergic purpura or pigmented purpuric dermatosis. Hyperpigmented macules occur in melasma, while hypopigmented ones appear in vitiligo or pityriasis alba.
• Papules: These may be associated with drug eruptions, milia, melanoma, neurodermatitis, cutaneous amyloidosis, xanthomatosis, lichen planus, or eczema.
• Maculopapular eruptions: These may indicate rubella, scarlet fever, or drug eruptions.
• Wheals: These are seen in urticaria, urticarial vasculitis, or drug eruptions.
• Vesicles/Blisters: Small blisters (vesicles) may suggest herpes simplex, chickenpox, or shingles. Large blisters (bullae) may indicate pemphigus or bullous pemphigoid. Pustules could result from infections (e.g., impetigo) or non-infectious conditions (e.g., palmoplantar pustulosis, pustular psoriasis)^[1].