Wolf's isotopic response

Until 1995, a case of psoriasis that developed within the dermatome of a previously healed herpes zoster was considered a Köbner phenomenon. R. Wolf introduced the term "isotopic reaction" in 1995 to describe "the appearance of a new skin disease at the site of another, unrelated and already healed skin disease". Originally, the term referred primarily to a preceding and healed herpes zoster. Later, the term "Wolf's isotopic reaction" was also used for a variety of other causative factors, such as healed cutaneous leishmaniasis, tinea, or varicella.

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).

Secondary diseases in the previously affected by disease area may be of different nature. Reported zosteriform infestation of:

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

The independence of this phenomenon is doubted (Happle R et al. 2018). Certainly, the reaction is not comparable to the classical Köbner phenomenon, in which a mechanical triggering is causative. 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 a previously X-ray irradiated skin area. The only difference is that the isotopic reaction does not follow a uniform pathogenetic pattern. The common basis in radiation recall is a previous (viral) disease that leaves a topical immunologic imbalance leading to increased pathologic 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 exanthematous and diffuse. It can be assumed that in these patients an earlier (in the meantime healed and forgotten) zoster disease could have led to this "recall pattern".

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