Diagnosis
When diagnosing Congenital Erythroipoetic Porphyria (Gunther Disease) one must exclude other forms of porphyria. These include Hepatoerythropoietic Porphyria and rare homozygous variants of Variegate Porphyria, Hereditary Coproporphyria, and STING-associated vasculopathy with onset in Infancy (SAVI). Mild variants may be present similarly to Porphyria Cutanea Tarda.There are four steps in establishing the diagnosis of any porphyria. First, a thorough history (particularly family history) and physical exam are performed with special attention paid to sun-exposed skin. Biochemical measurements of porphyrins and precursors in the urine, feces, and blood are necessary. Specialized labs are helpful in measuring activity of specific enzymes of the heme synthesis pathway and/or DNA and mutational analyses. In CEP, activity of uroporphyrinogen III synthase (the fourth enzyme in the heme biosynthetic pathway) will be markedly decreased.In congenital erythropoietic porphyria, urine aminolavulanic acid and porphobilinogen are typically normal. However, uroporphyrin and coproporphyrin tend to be markedly elevated and moderately elevated, respectively, in the urine more than in the feces. Additionally, fecal protoporphyrin is typically mildly elevated.In the red blood cells, uroporphyrin, coproporphyrin and protoporphyrin are all elevated, distinguishing this form of porphyria from the others. Finally, plasma analysis will demonstrate elevated uroporphyrin and coproporphyrin.Other nonspecific but helpful diagnostic clues are history of cutaneous photosensitivity, blistering, erosions, crusts and ulcerations leading to extensive scarring and deformation of the hands, loss of eyebrows, eyelashes with severe mutilation of cartilaginous structures like the nose, erythrodontia, and variable degree of hematologic involvement ranging from mild hemolytic anemia to intrauterine hydrops fetalis.
Hand-foot syndrome (Palmar-plantar erythrodysesthesia or PPE) -skin rash, swelling, redness, pain and/or peeling of the skin on the palms of hands and soles of feet
Stomach ulcers (This is seen more with the intra-arterial infusion). Contact your health provider immediately
Fever of 100.4 °F (38 °C) or higher, chills (possible signs of infection). Contact your health provider
Diarrhea (2 episodes in a 24-hour period)
Nausea (interferes with ability to eat and unrelieved with prescribed medication)
Vomiting (vomiting more than 4–5 times in a 24-hour period)
Mouth sores (painful redness, swelling or ulcers)
Unusual bleeding or bruising
Black or tarry stools, or blood in your stools
Blood in the urine
Yellowing of the skin or eyes
Tingling or burning, redness, swelling of the palms of the hands or soles of feet

Other
Fertility for both men and women may be affected by floxuridine. Use in research
Apart from its use in chemotherapy, floxuridine is also used in aging research employing a C. elegans model, namely to stop growth and to prevent reproduction. The latter is brought about by treatment of larvae close to maturity with low doses of floxuridine that, even though allowing normal maturation, causes reproducing individuals to lay eggs that are unable to hatch. This limits the population to a single generation allowing quantification of aging processes and measurement of longevity. It has, however, been indicated that floxuridin exposure by itself increases life expectancy potentially leading to flawed data in respective studies. History
Floxuridine first gained FDA approval in December 1970 under the brand name FUDR.