Patients with anhidrotic ectodermal dysplasia and immunodeficiency (EDA-ID) have mutations in the gene on the X chromosome encoding nuclear factor κB (NF-κB) essential modulator (NEMO), resulting in conical teeth, sparse hair, anhidrosis or hypohydrosis, and recurrent bacterial infections. The same gene is mutated in incontinentia pigmenti (IP), and mutations that do not completely abolish NF-κB activity allow survival of male fetuses. We present a case of a 1-year-old boy with a history of EDA-ID who was evaluated for an eruption that intermittently affected his scalp, upper back, cheeks, legs, and arms. A biopsy specimen taken from the back showed the presence of compact dyskeratotic cells with fragmented nuclei and numerous apoptotic keratinocytes scattered throughout the spinous and granular layer. The diagnosis of EDA-ID with IP was made. This case illustrates the complexity and overlapping features of the genodermatoses involving signaling pathways of the cell.