Small itchy papule is seen on the right hand. As a matter of fact, site of itchiness sometimes does not have any signs. The only thing we can see is the mark of scratching
Here we see an other small papule with some scaling resulting from repetitive scratching.
These two nodules on the elbow is very itchy. These are called scabietic nodules.
This is another scabetic nodule.
Scabetic nodules on penis and scrotum are pathognomonic for scabes
Scabetic nodules on penis and scrotum are pathognomonic for scabes
The above picture shows mother’s skin lesions. Not much scabetic nodules seen. Just some papules with scratch marks. Sometimes, there are scratch marks without papules.
The above picture shows mother’s skin lesions. Not much scabetic nodules seen. Just some papules with scratch marks. Sometimes, there are scratch marks without papules.
This is a picture borrowed from the internet showing a intra-epidermal burrow/tunnel. But this is very rarely found.
🩺 臨床病例報告：疥瘡 (Scabies)
病人資料
- 患者一：10 歲男童
- 患者二：其母親，年齡約 40 多歲
- 接觸史：一個半月前返回內地鄉村探望外公外婆，並居住於外公家中
家族病史
- 外公：一年前開始出現全身皮膚瘙癢，曾自行尋求偏方及外用藥膏，病情未見改善，未曾就醫。
- 外婆：於外公病發兩個月後亦出現全身瘙癢，病情相似，同樣未曾接受正規治療。
現病史
母子二人居住於外公家中一個半月。在返港前兩週，兩人開始出現全身瘙癢。返港後數天，因瘙癢難耐而求診。
臨床檢查
- 男童皮膚表現：
- 可見抓痕，但抓過的皮膚外觀基本正常
- 細心觀察下可見散在丘疹，部分丘疹表面有鱗屑，似為搔抓痕跡
- 特殊表現：在四肢皮膚及生殖器官（陰囊、陰莖）可見皮膚結節，此徵象具診斷意義，為疥瘡的特徵性病灶 (pathognomonic lesions)
診斷
- 臨床診斷：疥瘡 (Scabies)
治療方案
- 首選藥物：外用 Permethrin 5% 乳膏
- 塗抹範圍：頸部以下全身，包括軀幹、四肢、手指及腳趾縫隙、生殖器及肛門周圍
- 頭部通常不需塗抹，因疥瘡一般不累及頭皮
- 輔助治療：口服抗組織胺以緩解瘙癢
- 嚴重病例：可考慮短期口服類固醇以控制過敏反應
治癒後的瘙癢
即使疥蟎被殺死，皮膚瘙癢常持續數週，原因是機體對疥蟎抗原的過敏反應。若瘙癢嚴重，除抗組織胺外，可能需要口服類固醇以緩解症狀。
結論
此病例顯示疥瘡在家庭成員間的傳染性，並突顯了典型的病灶特徵（生殖器結節）。正確診斷及規範治療對於控制病情及防止家庭內部持續感染至關重要。
🩺 Clinical Case Report: Scabies
Patient Information
- Patient 1: 10‑year‑old boy
- Patient 2: His mother, in her 40s
- Exposure History: Returned to their rural hometown one and a half months ago to visit the boy’s grandparents, and stayed at the grandfather’s home.
Family History
- Grandfather: Developed generalized pruritus one year ago. Tried folk remedies and topical ointments without improvement. Did not seek medical care.
- Grandmother: Developed similar generalized pruritus two months after the grandfather’s onset. Also did not receive formal medical treatment.
Present Illness
The mother and child lived at the grandfather’s home for one and a half months. Two weeks before returning to Hong Kong, both began to experience generalized itching. A few days after returning, they sought medical attention due to unbearable pruritus.
Clinical Examination
- Boy’s skin findings:
- Scratch marks present, though the scratched areas appeared otherwise normal.
- Careful inspection revealed scattered papules, some with scaling, resembling scratch marks.
- Distinctive finding: skin nodules present not only on the limbs but also on the genitalia (scrotum and penis). These lesions are pathognomonic for scabies.
Diagnosis
- Clinical diagnosis: Scabies
Treatment Plan
- First‑line therapy: Topical Permethrin 5% cream
- Application: Entire body from the neck down, including trunk, arms, legs, finger and toe webs, genitalia, and perianal area.
- The head is usually spared, as scabies rarely affects the scalp.
- Adjunct therapy: Oral antihistamines to relieve itching.
- Severe cases: Short course of oral corticosteroids may be considered to control allergic response.
Post‑treatment Itching
Even after eradication of mites, pruritus often persists for several weeks due to allergic reaction to mite antigens. If itching is severe, in addition to antihistamines, oral corticosteroids may be required for symptom control.
Conclusion
This case highlights the contagious nature of scabies within family members and underscores the importance of recognizing its characteristic lesions, particularly genital nodules. Accurate diagnosis and standardized treatment are essential to control the disease and prevent ongoing household transmission.
學術討論：疥瘡
病原體與生活史
疥瘡由疥蟎（Sarcoptes scabiei）感染引起。疥蟎屬於寄生蟲，鑽入皮膚表皮層後寄居並繁殖。任何年齡層均可受感染，但免疫力低下者及長者更易罹患，因此醫院、幼兒中心及安老院舍偶有爆發報告。
疥蟎體型極小，肉眼難以辨認。雌蟎利用前足及口器鑽入皮膚，形成隧道並產卵。卵約三至四天孵化為幼蟲，十天後即可成熟繁殖。其生活史包括卵、幼蟲、若蟲及成蟲四期。雌蟎在隧道內一邊前進一邊產卵，每日可延伸 0.5–5 mm。夜間活動旺盛，因此患者夜間瘙癢尤為劇烈。
臨床表現
疥瘡的典型症狀包括：
- 夜間陣發性劇烈瘙癢。
- 手指縫可見灰褐色不規則曲線狀隧道，長約 2–4 mm。
- 皮疹多見於皮膚薄嫩處，如手指縫、小腹、乳房、腋窩、腹股溝及外生殖器，常呈粟米大小丘疹或丘皰疹。
- 疥瘡結節：常見於陰囊、陰莖、陰唇及腹股溝，呈黃豆大小淡紅色結節，伴劇烈瘙癢，且持續不消。
後期併發症
- 抓痕與血痂：因瘙癢劇烈，患者常不自覺搔抓。
- 繼發濕疹化：疥蟎分泌物及搔抓刺激皮膚，導致紅斑、水皰等，進一步加重瘙癢。
- 繼發感染：因搔抓、衛生不良或炎熱潮濕環境，易併發膿皰瘡及淋巴結腫大。
傳播途徑
疥瘡主要透過直接皮膚接觸傳播，患者衣物及被褥亦可成為媒介。家庭成員及院舍群體內傳播常見。雖可經性接觸傳播，但世界衛生組織建議不將其列為性病，以避免標籤化。
潛伏期
- 初次感染者：潛伏期約 2–6 週。
- 曾感染者：症狀可於 1–4 日內出現。
治療與管理
- 藥物治療：外用殺疥乳劑（如 Permethrin 5%）依醫囑塗抹全身頸部以下部位，並配合口服抗組織胺止癢。嚴重病例可考慮短期口服類固醇。
- 家庭與密切接觸者管理：患者家人及性伴侶需接受醫師評估並按需要治療。
- 防護措施：照護患者時應佩戴手套及保護衣，並徹底清潔雙手。
- 環境處理：患者衣物、毛巾及被褥需以 ≥60°C 熱水清洗 ≥10 分鐘；難以清洗的物品可密封於膠袋中至少 14 天。
預防方法
- 維持良好個人衛生，勤洗手及沐浴。
- 定期更換清潔衣物、毛巾及被褥。
- 避免共用衣物及個人物品。
- 院舍應定期檢查院友皮膚，以便及早發現感染。
Academic Discussion: Scabies
Pathogen and Life Cycle
Scabies is caused by infestation with Sarcoptes scabiei. These mites are parasites that burrow into the epidermis of the skin to reside and reproduce. People of all ages can be affected, but those with weakened immunity and the elderly are more susceptible. Outbreaks have occasionally been reported in hospitals, childcare centers, and long‑term care facilities.
Scabies mites are microscopic and invisible to the naked eye. Female mites use their forelegs and mouthparts to burrow into the skin, creating tunnels where they lay eggs. Eggs hatch into larvae in 3–4 days, and within about 10 days they mature and reproduce. The life cycle includes four stages: egg, larva, nymph, and adult. Females advance daily while laying eggs, extending tunnels by 0.5–5 mm. Because mites are more active at night, itching is typically most severe then.
Clinical Manifestations
Typical symptoms of scabies include:
- Paroxysmal intense itching at night.
- Burrows visible between fingers, 2–4 mm long, appearing as irregular gray‑brown lines.
- Skin lesions occur on thin, delicate areas such as finger webs, lower abdomen, breasts, axillae, groin, and genitalia. Lesions are usually papules or vesicles the size of millet grains.
- Scabetic nodules: Found on the scrotum, penis, labia, and groin. These pea‑sized reddish nodules are characteristic of scabies, often persistent and accompanied by severe itching.
Late‑Stage Complications
- Scratch marks and scabs: Due to intense itching, patients often scratch unconsciously.
- Secondary eczema: Mite secretions and scratching can cause erythema, papules, and vesicles, worsening pruritus.
- Secondary infection: Poor hygiene, scratching, or hot humid climates predispose to bacterial infection, pustules, and superficial lymphadenopathy.
Transmission
Scabies is usually spread through direct skin‑to‑skin contact. Clothing and bedding can also harbor mites and eggs, facilitating transmission. Household spread and institutional outbreaks are common. It can be sexually transmitted, especially among young adults with multiple partners, though the WHO advises against classifying it as a sexually transmitted disease to avoid stigmatization.
Incubation Period
- In individuals with no prior infection: 2–6 weeks.
- In previously infected individuals: symptoms may appear within 1–4 days.
Treatment and Management
- Medication: Topical scabicidal agents (e.g., Permethrin 5%) applied to the entire body below the neck, combined with oral antihistamines for itch relief. Severe cases may require a short course of oral corticosteroids.
- Household and close contacts: Family members and sexual partners should be evaluated and treated if necessary.
- Protective measures: Caregivers should wear gloves and protective clothing, and wash hands thoroughly before and after contact.
- Environmental control: Wash clothing, towels, and bedding at ≥60°C for at least 10 minutes. Items difficult to wash should be sealed in plastic bags for at least 14 days.
Prevention
- Maintain good personal hygiene, frequent handwashing and bathing.
- Regularly change and clean clothing, towels, and bedding.
- Avoid sharing clothing and personal items.
- Conduct routine skin checks in care facilities to detect infections early.