A man with
multiple myeloma and post-stem cell transplant cutaneous
graft-versus-host disease managed with systemic
prednisone and
sirolimus developed disseminated cutaneous
herpes simplex virus infection with virus-associated linear
ulcers of the inguinal folds and the area between his ear and scalp; the lesions at both sites had a distinctive "knife-cut" appearance. Using the PubMed database, an extensive literature search was performed on herpes simplex virus, immunocompromised patient, and "knife-cut sign".
RESULTS:
Herpes simplex virus infection-associated skin lesions that demonstrate the "knife-cut sign" present in patients who are immunosuppressed secondary to either an underlying medical condition or a systemic
therapy or both. The distinctive virus-related cutaneous lesions appear as linear
ulcers and fissures in intertriginous areas, such as the folds in the inguinal area, the vulva, and the abdomen; in addition, other sites include beneath the breast, within the gluteal cleft, and the area between the ear and the scalp. Not only
herpes simplex virus-2, but also
herpes simplex virus-1 has been observed as the causative viral serotype; indeed,
herpes simplex virus-1 has been associated with genital and inframammary lesions in addition to those above the neck. Direct fluorescent antibody testing is a rapid method for confirming the clinically suspected
viral infection; however, since false-negative direct fluorescent antibody testing occurred in some of the patients, it may be prudent to also perform viral cultures and possibly lesional skin biopsies to establish the diagnosis. The
herpes simplex virus infection-related skin lesions clinically improve once systemic
antiviral therapy is initiated.
CONCLUSION: In immunosuppressed individuals, the "knife-cut sign" is a distinctive presentation of cutaneous linear erosive
herpes simplex virus infection. Recognition of the linear
ulcers in intertriginous areas and body folds should prompt the clinician to consider
herpes simplex virus infection-associated skin lesions in an immunocompromised patient and to initiate systemic
antiviral treatment while awaiting the results of laboratory evaluation to confirm the suspected diagnosis.