Paronychia

Disease Description (Causes and Symptoms)

• Definition: Pruritus ani is a symptom in which the anus and surrounding skin (including the perineum and vulva) are persistently or intermittently intensely itchy; it is a symptom rather than a separate disease.
• Main causes
  • Local irritation: residual stool after bowel movements, excessive cleansing (soap·strong washing), colored or scented toilet paper·wet wipes, hygiene sprays, topical products such as suppositories·ointments
  • Diet·medications: spicy foods, coffee·tea·cola·milk·alcohol·chocolate·citrus fruits·tomatoes, high-dose vitamin C, intestinal flora imbalance caused by antibiotics
  • Anal·rectal diseases: hemorrhoids, anal fissures, anal fistulas, anal polyps, rectal cancer, etc.
  • Infections·parasites: pinworms (Enterobius), fungi (such as Candida), bacterial infections
  • Skin diseases: eczema, psoriasis, seborrheic dermatitis, etc.
  • Psychological factors: may be associated with stress, anxiety, and sexual stimulation
• Summary of pathophysiology
  • The area around the anus has a high concentration of sensory nerves, so even minor irritation can trigger a strong itching response. When the itch–scratch cycle is repeated, the skin becomes thickened (lichenification), and inflammation·fissures·secondary infections can develop.
• Clinical symptoms
  • Intolerable itching (especially worsening at night), redness·erosions·skin thickening caused by scratching (a leathery appearance), pain (in cases of infection·fissures), surface fissures·moisture·signs of fungal infection, or well-demarcated lesions (psoriasis), etc.

Treatment Methods

• Basic principles: Identify and eliminate the cause (if possible) → topical·symptomatic treatment → treatment of the underlying disease when necessary
• Lifestyle management (first-line treatment)
  • Anal hygiene: Gently wash with lukewarm water and do not use irritating soaps·fragrances·colorants. After washing with water, gently pat dry and dry the area completely.
  • When using toilet paper, unscented·uncolored products are recommended; for wet wipes, products that are less irritating are recommended. Avoid excessive rubbing.
  • Underwear: Wear breathable cotton underwear and avoid tight clothing. Manage weight and sweating.
  • Avoid foods: Temporarily stop foods associated with worsening symptoms (spicy foods, coffee·tea·alcohol·milk, etc.) and observe the response.
  • Do not scratch: When itchy, do not scratch; wash with lukewarm water. If necessary, consider a sedating antihistamine for nighttime use (as a sleep aid).
• Topical medications
  • Low-potency topical steroids (short-term, e.g., within 1 week if necessary): intended to relieve acute inflammation. Long-term use carries a risk of skin atrophy.
  • Topical antifungals: When a fungal infection (Candida) is suspected.
  • Topical immunomodulators (such as tacrolimus): Limited use when steroids are difficult to use (at the physician’s discretion).
  • Moisturizers·protective agents: Intended to maintain the skin barrier.
  • Topical antibiotics/topical anesthetics: Not generally recommended for use (risk of irritation·allergic reactions).
• Systemic medications
  • Oral antihistamines (especially sedating agents when there are sleep disturbances)
  • Anthelmintics when a parasitic infection is suspected (pinworms: mebendazole·albendazole, etc.) — consider simultaneous treatment of family members
• Treatment of the underlying disease
  • Anal diseases such as hemorrhoids·anal fissures·anal fistulas require the appropriate treatment (conservative·surgical).
  • Chronic·refractory cases: Surgical options such as nerve-block injections (alcohol injections, etc.), skin peeling·excision·grafting may be considered, but limited indications and complications must be taken into account.
• Other (depending on the case)
  • In rare cases, topical capsaicin, oral neuromodulators (such as gabapentin), etc. have been reported to be used, but expert judgment and potential adverse effects must be considered.

Checklist Before an Outpatient Visit (Including Preparation Items·Sample Questions)

• Items and records to prepare
  • A list of currently taken medications (including prescriptions·OTC medications·vitamins·herbal medicines)
  • A recent diet record (mark foods associated with worsening symptoms)
  • Symptom diary: time of onset (day/night), times when symptoms are most severe, triggers, frequency/intensity of scratching, factors that improve·worsen symptoms
  • Photos of the affected area (if possible)
  • Recent test results (stool tests, skin tests, anal-related tests, etc.) or records of previous surgeries·diagnoses
• Items the doctor may check during the consultation (anticipated questions)
  • When the symptoms began and how they have progressed
  • Bowel habits (frequency·form) and how the area is managed after bowel movements
  • Suppositories·ointments·types of toilet paper·cleansers currently being used
  • Location of the itching (localized around the anus vs. including the vulva), and whether it worsens at night
  • Similar symptoms among family members (related to pinworm infection)
  • History of skin diseases (psoriasis·eczema) or anal diseases

Examples of General Questions to Ask the Doctor

• What is the most likely cause of this itching? Are additional tests needed?
• What is the recommended duration of use and what are the side effects of the topical treatment?
• Are there any items that I must avoid in my diet·lifestyle habits?
• If the symptoms do not improve, what is the next step (tests·treatment)?

Examples of Disease-Specific Questions

• How can we determine for sure whether my pruritus ani is caused by hemorrhoids or rectal disease? (Need for anoscopy·digital rectal examination·stool tests, etc.)
• If pinworms are suspected as the cause, should all family members be treated? How can reinfection be prevented?

(Prognosis summary) In most cases, symptoms improve within 1 week and are relieved within 1 month with elimination of the cause and appropriate conservative treatment. If the condition becomes chronic, skin changes·secondary infections·sleep disturbances, etc. may persist, so identifying the cause and receiving appropriate treatment are important.