Transverse melanonychia secondary to total skin electron beam therapy: A report of 3 cases

Melanonychia

“…Iatrogenic causes of melanocytic activation include medications (especially chemotherapeutic agents) [17–19], phototherapy, X-ray exposure, and electron beam therapy [20] (Figure 3, Table 2) [2]. Presentations of iatrogenically-induced melanonychia may vary significantly depending on the exposure, but are usually associated with melanonychia of several fingernails and toenails [2].…”

“…Transverse melanonychia has occurred in conjunction with use of the following: electron beam therapy [20], conventional radiographic therapy to treat hand dermatitis (used in the 1950s and 1960s) [21, 22], psoralen with ultraviolet A (PUVA) [23–26], infliximab [27], zidovudine [28], prolonged antimalarial therapy with amodiaquine, chloroquine, mepacrine, or quinacrine [2, 26, 28], and chemotherapy with agents such as doxorubicin, bleomycin, cyclophosphamide, daunorubicin, dacarbazine, 5-fluorouracil, methotrexate [20], and hydroxyurea [26, 29, 30]. Transverse melanonychia associated with electron beam therapy and PUVA is benign and typically resolves with the cessation of treatment [20, 23, 26]. Interestingly, for antimalarials amodiaquine, chloroquine, and mepacrine, transverse melanonychia may be attributable to either melanin production or more commonly ferric dyschromia [2].…”

Benign pigmentation of nails

“…Certain diseases like Addison's disease, Albright syndrome, lichen planus, drugs, cyanocobalamine deficiency, and AIDS are commonly accompanied by cutaneous and mucosal pigmentation. [1,6] Medications (especially chemotherapeutic agents), [7,8] phototherapy, X-ray exposure, and electron beam therapy [1,9] Are the important causes of iatrogenically induced melanonychia. Syndrome-associated melanonychia, which occurs in conjunction with Laugier-Hunziker, Peutz-Jeghers, and Touraine syndromes, typically involves multiple digits, and also mucosal pigmented macules involving the lips and oral cavity.…”

Polydactylous Longitudinal Melanonychia Acquired following Total Skin Electron Beam Radiation Therapy for Sézary Syndrome

“…We find this unique observation of acquired polydactylous LM as a side effect of TSEBT important for physicians to understand. There is a single report of 3 cases of transverse melanonychia on multiple fingernails following TSEBT for mycosis fungoides (1 African-American, 2 Caucasian) where the pigmentation was displaced outwards as the nails grew [2]. However, this is the first case of LM seen after TSEBT for cutaneous T-cell lymphoma (CTCL).…”