Some investigators have used the parenteral formulation orally to treat patients with hairy cell leukemia. About 37–51% of oral cladribine is bioavailable orally. It is used, often in combination with other cytotoxic agents, to treat various kinds of histiocytosis, including Erdheim–Chester disease and Langerhans cell histiocytosis.Following EMA approval of cladribine tablets for the treatment of adult patients with highly active relapsing-remitting multiple sclerosis in 2017, as of July 2020, cladribine tablets have gained marketing authorisation in over 75 countries. In 2019, cladribine tablets were approved by the FDA for the treatment of relapsing forms of multiple sclerosis, to include relapsing-remitting disease and active secondary progressive disease, in adult patients who have had an inadequate response to, or are unable to tolerate, an alternate drug indicated for the treatment of multiple sclerosis.Cladribine may cause foetal harm when administered to a pregnant woman and is listed by the FDA as pregnancy category D; safety and efficacy in children has not been established. Mechanism of action
As a purine analogue, cladribine (2-chloro-2-deoxyadenosine [2-CdA]) is taken up into rapidly proliferating cells, including B and T lymphocytes, to be incorporated into DNA synthesis. Chemically, it mimics nucleoside adenosine; however, unlike adenosine, cladribine has a chlorine molecule at position 2, which renders it partially resistant to breakdown by adenosine deaminase. This causes it to accumulate in cells and interfere with the targeted cells ability to process DNA.Cladribine is taken up by specific nucleoside transporter proteins.
Pigmented purpuric dermatosis refers to one of the three major classes of skin conditions characterized by purpuric skin eruptions. Pigmented purpuric dermatosis are distinguished from other purpura by size (0.3–1 cm) and are most often seen in the lower extremities. : 829   Pigmentary purpuric eruptions may present with one of several clinical patterns. There may be overlapping characteristics among pigmented purpuric dermatosis and between their signs and those of other purpuric eruptions. : 829   Examples of the pigmented purpuric dermatosis group include:: 829–30 
Schambergs disease
Majocchis disease (Purpura annularis telangiectodes)
Gougerot-Blum syndrome (Pigmented purpuric lichenoid dermatitis)
Ducas and Kapetanakis pigmented purpura
Lichen aureusAlthough vascular damage may be present, it is insufficient for these conditions to be considered forms of vasculitis.A few very small non-blinded studies of treatment with narrow-band ultraviolet light have been reported as promising. See also
Purpura
Skin lesion
List of cutaneous conditions

References


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