Wolf's isotopic response

The phenomenon of the "isotopic or isotopic reaction" or "isotopic response" describes the occurrence of a secondary, new skin disease at the site of a previously healed disease. In the vast majority of cases, the secondary disease is preceded by a zoster infection, more rarely by a herpes simplex infection. The time interval between the two diseases can be a few days, months or even years (median 4 months).

Ultimately, the pathogenesis of the isotopic reaction is not precisely known. It can be assumed that persistent viral, bacterial or other antigens could be responsible for the local "hypersensitivity reaction" (Lora V et al. 2014).

The secondary diseases in the previously affected area can be of different nature. The zosteriform infestation of:

• Impetigo contagiosa after previous zoster (Cohen PR 2015)
• Zosteriform lichen planus (Lora V et al. 2014)
• Zosteriform bullous pemphigoid
• Morphea (Noh TW et al. 2011)
• Cutaneous metastases of breast carcinomas, basal cell carcinomas, squamous cell carcinomas (?).
• Kaposi's sarcoma
• Cutaneous sarcoidosis
• Angiosarcoma (Kowalzick L et al. 2013)
• Eosinophilic dermatosis in hematologic neoplasia (Jin A et al. 2019)

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Case report (morphea in healed zoster): Noh TW et al (2011) A 57-year-old Korean man presented with an 8-month history of indurated plaques on the right chest and upper back. One year earlier, the patient had developed painful vesicles in dermatomes T2-4 on the right, which had been diagnosed as herpes zoster. He was treated with oral antiviral medication and analgesics, and the lesions had disappeared one month after the onset of the outbreak. Three months after the complete resolution of the herpes zoster, new hardened plaques had formed at the site of the previously healed herpes zoster. The lesions had spread slowly. Clinical examination revealed atrophic, hypopigmented, indurated plaques in dermatomes T2-4 on the right, all of which corresponded to the site of the healed herpes zoster (Fig. 1). The plaques were confined to the former zoster scar. The patient's new lesions were itch-free and he complained of intermittent, mild postherpetic neuralgia. He reported a history of diabetes mellitus and laboratory values were within normal limits. The serologic test for Borrelia burgdorferi was negative.

The independence of this phenomenon is doubted (Happle R et al. 2018). The reaction is certainly not comparable with the classic Köbner phenomenon, which is caused by a mechanical trigger. Type II of the Köbner phenomenon, the pseudo-Köbner phenomenon, is also primarily mechanically triggered.

The isotopic reaction is most comparable to the"radiation recall phenomenon", a dermatitic flare-up phenomenon in an area of skin previously exposed to X-rays. However, the isotopic reaction does not follow a uniform pathogenetic pattern. The common basis of radiation recall is a (viral) pre-existing disease, which leaves a topical immunological imbalance that leads to increased pathological reactivity.

Incidentally, some cases of the recently described"eosinophilic dermatosis in hematologic neoplasia" show exactly this reaction pattern. Here, too, a zosteriform pattern of spread is found in a disease that is in itself exanthematic and diffuse. It can be assumed that a previous (now healed and forgotten) zoster disease may have led to this "recall pattern" in these patients.

1. Cohen PR (2015) Zosteriform impetigo: Wolf's isotopic response in a cutaneous immunocompromised district. Dermatol Pract Concept 5:35-39.
2. Gurel MS et al (2016) Zosteriform pemphigoid after zoster: Wolf's isotopic response. Int Wound J 13:141-142.
3. Jin A et al (2019) Eosinophilic dermatosis of hematologic malignancy responding to dupilumab in a patient with chronic lymphocytic leukemia. JAAD Case Rep 5:815-817.
4. Kowalzick L et al. (2013) Wolf's isotopic response: local cutaneous B-cell lymphoma infiltration after herpes zoster N. trigeminus 1. In: Dermatology from case to case. Kowalzick L et al. Dermatology from case to case. Gerog Thieme Publishers
5. Lora V et al. (2014) Zosteriform lichen planus after herpes zoster: report of a new case of Wolf's isotopic phenomenon and literature review. Dermatol Online J 20:13030/qt5vf99178.
6. Lucas-Truyols S et al (2017) Eosinophilic dermatosis of hematologic malignancy. Actas Dermosifiliogr 108:e39-e44.
7. Noh TW et al (2011) Morphea developing at the site of healed herpes zoster. Ann Dermatol 23:242-245.
8. Wang T et al. (2019) Wolf's isotopic response after herpes zoster infection: A Study of 24 New Cases and Literature Review. Acta Derm Venereol 99: 953-959.
9. Wolf R et al (1995) Isotopic response. In t J Dermatol 34: 341-348