Contact allergies in certain types of employment are especially problematic, particularly if the work involves the handling of allergenic materials, e.g. masonry work or hairdressing. People allergic to Balsam of Peru may experience a flare-up of hand eczema if they use or consume products that use it as an ingredient.Severe and chronic eczema qualifies as one of the most frequent occupational illnesses. Patients should therefore be referred to an occupational-dermatological specialist as soon as possible. Patients with a history of neurodermitis, hay fever, or allergic asthma often develop hand eczema. These sicknesses reflect the individuals particular susceptibility or genetic predisposition to react over-sensitively to various environmental influences. This is described as atopy or atopy diathesis. Atopic diathesis is frequently accompanied by genetically conditioned problems with the skins protective barriers, which causes a weakening of the skins resistance against irritating substances and moisture, as well as easier penetration by allergens, which may lead to the development of contact allergies. Differences according to prevailing signs of skin illness (morphology)
The clinical appearance of various subtypes of hand eczema differs. The term dyshidrotic hand eczema is used to describe formations that mainly exhibit pronounced, itching blister formations, while callus and tear formations typically indicate hyperkeratotic fissured hand eczema. Differences according to degree of severity and course
Independent of the triggering cause or the prevailing signs of skin illness, the selection and planning of treatment options is important, since different types of illness also differ in terms of their degree of severity and the course of the illness.
Diagnosis
Types
Type I tyrosinemia can be detected via blood tests for the presence of a fumarylacetoacetate metabolite, succinylacetone, which is considered a pathognomonic indicator for the disease.Type II tyrosinemia can be detected via the presence of significantly elevated plasma tyrosine levels, and the diagnosis can be confirmed by detection of a mutation in TAT in cultured fibroblasts.Type III tyrosinemia can be diagnosed by detection of a mutation in HPD in cultured fibroblasts. Treatment
Treatment varies depending on the specific type; a low-protein diet combined with the use of a specially engineered formula to supply protein is required in most cases. Experience with nitisinone has shown it to be effective, especially when started within the first month of life, and it is now the standard course of treatment. It is a 4-hydroxyphenylpyruvate dioxygenase inhibitor indicated for the treatment of hereditary tyrosinemia type 1 (HT-1) in combination with dietary restriction of tyrosine and phenylalanine. Liver transplant is indicated for patients with tyrosinemia type I who do not respond to nitisinone, as well as those with acute liver failure and hepatomas. See also
Alkaptonuria
Inborn error of metabolism
Ochronosis

References
External links

GeneReview/NCBI/NIH/UW entry on Tyrosinemia Type 1
Tyrosinemia on Genetic Home Reference