Dermatology Online Journal

What is the mechanism of Koebner phenomenon in Henoch-Schönlein purpua?
Jae Il Shin MD, Jae Seung Lee MD
Dermatology Online Journal 14 (12): 17

Department of Pediatrics, The Institute of Kidney Disease, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Korea. jsyonse@yumc.yonsei.ac.kr

---

Comment on: Koebner's phenomenon in Henoch-Schönlein purpura and role of pressure in its causation. (Dermatol Online J. 2007 May 1;13(2):26.)

Although the exact mechanism of the Koebner phenomenon has not been elucidated in Henoch-Schönlein purpura (HSP), tryptase (a marker for mast cell activation) may play an important role in the pathogenesis.

We read with interest the article by van Nischal et al [1]. They reported a 42-year-old male with Henoch-Schönlein purpura (HSP) showing Koebner's phenomenon [1], but the exact patho-mechanism was not elucidated. Namazi [2] reported that increase of tryptase levels following trauma could also provide a mechanism for the Koebner phenomenon seen in psoriasis and Naukkarinen et al. [3] also showed that mast cell tryptase and chymase are potential regulators of neurogenic inflammation in psoriatic skin. Therefore, tryptase may play an important role in the pathogenesis of the Koebner phenomenon. Although not extensively studied in vasculitis, recent studies showed that immuno-enzyme-histological staining of tryptase (a marker for mast cell activation) was found in cutaneous allergic vasculitis [4] or HSP nephritis [5]. Therefore, further studies should be performed to elucidate the relationship between mast cell activation and the Koebner phenomenon in the acute stage of HSP.

References

1. Nischal KC, Uday K, Urmila B. Koebner's phenomenon in Henoch Schoenlein purpura and role of pressure in its causation. Dermatol Online J. 2007 May 1;13(2):26. [PubMed]

2. Namazi MR. Possible molecular mechanisms to account for the involvement of tryptase in the pathogenesis of psoriasis. Autoimmunity. 2005 Sep;38(6):449-52. [PubMed]

3. Naukkarinen A, Harvima IT, Aalto ML, Horsmanheimo M. Mast cell tryptase and chymase are potential regulators of neurogenic inflammation in psoriatic skin. Int J Dermatol. 1994 May;33(5):361-6. [PubMed]

4. Inamura H, Igarashi Y, Kashiwase Y, Morioka J, Suzuki K, Kurosawa M. Mast cells in cutaneous allergic vasculitis: a case report. Allergol Int. 2006 Sep;55(3):343-5. [PubMed]

5. Chen Y, Zhou JH, Wu HS, Wang HW. Role of mast cells and eosinophil cationic protein in the pathogenesis of Henoch-Schonlein purpura nephritis. Zhonghua Er Ke Za Zhi. 2006 Jun;44(6):407-10. [PubMed]

© 2008 Dermatology Online Journal