Urticaria pigmentosa
Urticaria pigmentosa は、皮膚肥満細胞症の最も一般的な形態です。これは、皮膚内の過剰な数の肥満細胞によって引き起こされ、刺激を受けると皮膚に蕁麻疹や病変が生じるまれな病気です。赤または茶色の斑点が皮膚、通常は胸、額、背中の周りに見られることがよくあります。これらの肥満細胞は、刺激を受けると（皮膚をこすったり、熱にさらされるなど）、ヒスタミンを過剰に生成し、アレルギー反応を引き起こして、刺激部位に限局した蕁麻疹（「ダリエ徴候」と呼ばれることもあります）を引き起こします。
References
Mastocytosis は、皮膚、骨髄、消化器系などの体のさまざまな部分によく見られる、肥満細胞が過剰に存在する状態です。世界保健機関 (WHO) によると、 cutaneous mastocytosis は主に 3 つのタイプに分類できます。最初のタイプ (mastocytomas) は、孤立性または少数 (≤3) の病変で構成されます。 2 番目のタイプ (urticaria pigmentosa) は複数の病変を伴い、通常は 10 個以上から 100 個未満の範囲に及びます。最後のタイプは、皮膚全体にわたる広範な病変を示します。 Urticaria pigmentosa は、小児における皮膚肥満細胞症の最も一般的な形態ですが、成人でも発生する可能性があります。通常は無害な症状であり、思春期に改善することがよくあります。成人の肥満細胞症とは異なり、 urticaria pigmentosa が内臓に影響を与えることはほとんどありません。 urticaria pigmentosa の特徴の 1 つは、一般に蕁麻疹として知られる、皮膚に小さなかゆみのある赤褐色または黄褐色の斑点や病変を引き起こす傾向があることです。これらの斑点は通常、小児期に現れ、生涯続く可能性があります。
Mastocytosis is a disorder characterized by mast cell accumulation, commonly in the skin, bone marrow, gastrointestinal (GI) tract, liver, spleen, and lymphatic tissues. The World Health Organization (WHO) divides cutaneous mastocytosis into 3 main presentations. The first has solitary or few (≤3) lesions called mastocytomas. The second, urticaria pigmentosa (UP), involves multiple lesions ranging from >10 to <100 lesions. The last presentation involves diffuse cutaneous involvement. UP is the most common cutaneous mastocytosis in children, but it can form in adults as well. It is considered a benign, self-resolving condition that often remits in adolescence. Unlike adult forms of mastocytosis, there is rarely any internal organ involvement in UP. What makes UP particularly distinctive is its tendency to manifest as small, itchy, reddish-brown, or yellowish-brown spots or lesions on the skin, commonly referred to as urticaria or hives. These spots typically appear in childhood and can persist throughout a person's life.
Mastocytosis is a disorder characterized by mast cell accumulation, commonly in the skin, bone marrow, gastrointestinal (GI) tract, liver, spleen, and lymphatic tissues. The World Health Organization (WHO) divides cutaneous mastocytosis into 3 main presentations. The first has solitary or few (≤3) lesions called mastocytomas. The second, urticaria pigmentosa (UP), involves multiple lesions ranging from >10 to <100 lesions. The last presentation involves diffuse cutaneous involvement. UP is the most common cutaneous mastocytosis in children, but it can form in adults as well. It is considered a benign, self-resolving condition that often remits in adolescence. Unlike adult forms of mastocytosis, there is rarely any internal organ involvement in UP. What makes UP particularly distinctive is its tendency to manifest as small, itchy, reddish-brown, or yellowish-brown spots or lesions on the skin, commonly referred to as urticaria or hives. These spots typically appear in childhood and can persist throughout a person's life.
6 歳の女の子が、最初は頭皮にできた黒い斑点がいくつかあり、その後 6 か月間で顔や体に広がりました。彼女は、圧力がかかると腫れ、赤くなり、かゆみを感じると述べました。彼女は顔面紅潮、嘔吐、下痢、喘鳴などの症状を経験しておらず、彼女の個人および家族の病歴からは関連する手がかりが得られませんでした。検査の結果、彼女の頭皮、額、顔、首に複数の黒い斑点があり、胸と背中にわずかに隆起した黒い斑点があることがわかりました。シミを軽くこすると、2 分以内に腫れとかゆみが生じましたが、症状は 15 ～ 20 分以内に消えました (Darier's sign) 。
A 6-year-old female, presented with multiple dark-colored lesions, which started over the scalp and further progressed to involve the face and trunk since past six months. She gave a history of elevation, redness, and itching on the lesions on application of pressure. There was no associated flushing, vomiting, diarrhoea, or wheeze. The personal and family history was not contributory. On examination, there were multiple hyperpigmented macules over the scalp, forehead, face, and neck in addition to minimally elevated hyperpigmented plaques over the chest and the back. Gentle rubbing of the lesions elicited urtication and itching within 2 min and it resolved within 15–20 minutes, suggestive of the Darier's sign.
A 6-year-old female, presented with multiple dark-colored lesions, which started over the scalp and further progressed to involve the face and trunk since past six months. She gave a history of elevation, redness, and itching on the lesions on application of pressure. There was no associated flushing, vomiting, diarrhoea, or wheeze. The personal and family history was not contributory. On examination, there were multiple hyperpigmented macules over the scalp, forehead, face, and neck in addition to minimally elevated hyperpigmented plaques over the chest and the back. Gentle rubbing of the lesions elicited urtication and itching within 2 min and it resolved within 15–20 minutes, suggestive of the Darier's sign.
