Striate palmoplantar keratoderma (also known as "Acral keratoderma," "Brünauer-Fuhs-Siemens type of palmoplantar keratoderma," "Focal non-epidermolytic palmoplantar keratoderma," "Keratosis palmoplantaris varians," "Palmoplantar keratoderma areata," "Palmoplantar keratoderma striata," "Wachter keratoderma,": 778, 785  and "Wachters palmoplantar keratoderma") is a cutaneous condition, an autosomal dominant keratoderma principally involving the soles with onset in infancy or the first few years of life. : 509 Type 1:  148700: DSG1
Type 2:  612908: DSP
Type 3:  607654: KRT1
Carvajal syndrome (also known as "Striate palmoplantar keratoderma with woolly hair and cardiomyopathy" and "Striate palmoplantar keratoderma with woolly hair and left ventricular dilated cardiomyopathy,") is a cutaneous condition inherited in an autosomal recessive fashion, and due to a defect in desmoplakin. : 811  Striate palmoplantar keratoderma, woolly hair, and left ventricular dilated cardiomyopathy has been described in both autosomal dominant and autosomal recessive forms, but only the recessive forms have a clear association with dilated cardiomyopathy. : 513  The skin disease presents as a striate palmoplantar keratoderma with some nonvolar involvement, particularly at sites of pressure or abrasion. : 513 
Scleroatrophic syndrome of Huriez (also known as "Huriez syndrome," "Palmoplantar keratoderma with scleroatrophy," "Palmoplantar keratoderma with sclerodactyly," "Scleroatrophic and keratotic dermatosis of the limbs," and "Sclerotylosis") is an autosomal dominant keratoderma with sclerodactyly present at birth with a diffuse symmetric keratoderma of the palms and soles. : 513 : 576  An association with 4q23 has been described. It was characterized in 1968.
Adverse effects
The medication has two FDA "black box" warnings: One raises concerns that use before or during pregnancy by either sex may result in birth defects in the baby, and the other is regarding the risk of red blood cell breakdown.Ribavirin should not be given with zidovudine because of the increased risk of anemia; concurrent use with didanosine should likewise be avoided because of an increased risk of mitochondrial toxicity. Mechanisms of action
It is a guanosine (ribonucleic) analog used to stop viral RNA synthesis and viral mRNA capping, thus, it is a nucleoside inhibitor. Ribavirin is a prodrug, which when metabolized resembles purine RNA nucleotides. In this form, it interferes with RNA metabolism required for viral replication. Over five direct and indirect mechanisms have been proposed for its mechanism of action. The enzyme inosine triphosphate pyrophosphatase (ITPase) dephosphorylates ribavirin triphosphate in vitro to ribavirin monophosphate, and ITPase reduced enzymatic activity present in 30% of humans potentiates mutagenesis in hepatitis C virus. RNA viruses
Ribavirins amide group can make the native nucleoside drug resemble adenosine or guanosine, depending on its rotation. For this reason, when ribavirin is incorporated into RNA, as a base analog of either adenine or guanine, it pairs equally well with either uracil or cytosine, inducing mutations in RNA-dependent replication in RNA viruses. Such hypermutation can be lethal to RNA viruses.