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monoclonal antibody, and ultrastructural studies. Int J Dermatol 1988; 27: 487–490. 8 Carter JD, Valeriano J, Vasey FB. Hydroxychloroquine as a treatment for atrophoderma of Pasini and Pierini. Int J Dermatol 2006; 45: 1255–1256. 9 Arpey CJ, Patel DS, Stone MS, et al. Treatment of atrophoderma of Pasini and Pierini-associated hyperpigmentation with the Q-switched alexandrite laser: a clinical, histologic, and ultrastructural appraisal. Lasers Surg Med 2000; 27: 206–212. 10 Miller RF. Idiopathic atrophoderma. Arch Dermatol 1965; 92: 653–660.
Pyoderma gangrenosum after aortic aneurysm repair: an umpteenth example of immunocompromised district
Editor, We read with great interest a recent paper by Leventhal et al.,1 published in the November issue of the International Journal of Dermatology. In their work, the authors1 reported a 72-year-old man who developed pyoderma gangrenosum (PG) at the site of surgical incision soon after an aortic aneurysm repair. In describing a possible pathogenic explanation of this rare event, the authors1 referred to pathergic PG, an uncommon variant of PG that develops in traumatized areas. Although interesting, this definition of pathergic PG does not give an exhaustive view of the pathomechanisms of postoperative PG. Local vulnerability in dermatology is an old but currently valid concept which allows for the rapid and intuitive explanation of why a skin disease may assume a peculiar distribution by remaining confined to a given site. In recent years, the pathogenic concept of the cutaneous immunocompromised district (ICD) has gained increasing credence among dermatologists as it offers an overall perspective on the occurrence of skin disorders at cutaneous sites that have been previously marked, and therefore immunodestabilized, by an injuring clinical event (e.g. lymphedema, herpes zoster infection, radiation, burn, vaccination, trauma, or neurologic injury).2–6 In abdominal wall surgery, it seems obvious that tissue incision may inevitably damage cutaneous nerve fibers, thus altering the so-called neuroimmunocutaneous system. This destabilization would consequently render that traumatized cutaneous site prone to the occurrence of an opportunistic cutaneous disease, such as PG in this case. Moreover, we think the adjective pathergic is unsuitable for a newly occurring PG that appears on a surgical scar, such as in the case described by Leventhal et al.1 In fact, the term pathergy is used to describe hyper-reactivity of the skin that occurs as a consequence of minimal trauma and is also used to indicate a particular reaction to needle International Journal of Dermatology 2015, 54, e38–e55
insertion in Behcßet’s disease and in PG.7 Therefore, a skin pathergy test is positive in a patient already affected by a specific disease. From a dermatologic point of view, a pathergic response may be likened to the Koebner phenomenon, which refers to the appearance of a new lesion of a pre-existing skin disorder at the site of an injury of any kind.8 In conclusion, in the case reported by Leventhal et al.,1 the new occurrence of PG at a traumatized site cannot be considered a pathergic phenomenon but instead represents a typical umpteenth example of an ICD because the patient was not affected by PG before surgery. We think that our observation will be useful in helping clinicians to easily recognize in these rare situations the differences between a real sensu stricto pathergic reaction (when the patient is already affected by the disease) and a classical occurrence of an ICD.
Vincenzo Piccolo, MD Adone Baroni, MD, PhD Teresa Russo, MD Eleonora Ruocco, MD, PhD Department of Dermatology and Venereology Second University of Naples Naples Italy E-mail:
[email protected] References 1 Leventhal JS, Tlougan BE, Mandell JA, et al. Postoperative pathergic pyoderma gangrenosum after aortic aneurysm repair. Int J Dermatol 2013; 52: 1401–1403. 2 Ruocco V, Brunetti G, Puca RV, et al. The immunocompromised district: a unifying concept for lymphoedematous, herpes-infected and otherwise damaged sites. J Eur Acad Dermatol Venereol 2009; 23: 1364–1373. 3 Baroni A, Piccolo V, Russo T, et al. Recurrent blistering of the fingertips as a sign of carpal tunnel syndrome: an effect of nerve compression. Arch Dermatol 2012; 148: 545–546. 4 Piccolo V, Russo T, Baroni A. Unilateral bullous pemphigoid in hemiplegic patients: an instance of immunocompromised district. J Dermatol 2012; 40: 64–65. 5 Baroni A, Russo T, Piccolo V, et al. Opportunistic metastatic porocarcinoma after saphenous venectomy for coronary bypass surgery. Clin Exp Dermatol 2013; 38: 507–510. 6 Baroni A, Piccolo V, Russo T. A possible explanation for the high frequency of contact sensitization in chronic venous ulcers. Int Wound J 2013; [Epub ahead of print. doi: 10.1111/iwj.12108.] 7 Varol A, Seifert O, Anderson CD. The skin pathergy test: innately useful? Arch Dermatol Res 2010; 302: 155–168. 8 K€ obner H. Zur Aetiologie der Psoriasis. Vierteljahresschr Dermatol 1876; 3: 559–561.
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