Challenges encountered in dermatologic drug development.

Few truly new drugs are developed primarily for the treatment of dermatologic diseases. We discuss challenges and special considerations of dermatology drug development which contribute to this relative absence of novel drugs in dermatology. The issues considered are: a) the economic potential of dermatologic drugs including the potential return on investment (ROI); b) the benefit-to-risk ratio for treatments of skin disease; c) the relative absence of surrogate end points for topically applied drugs; d) drug penetration and vehicles; e) shelf life, stability, emulsifiers, preservatives; f ) contact irritancy, contact allergy, contact photoallergy and photocarcinogenicity; g) drugs with more than one active; h) semi-quantitative or soft primary end points; i) inadequate basic knowledge of pathophysiology of skin diseases. Of the many challenges, we conclude it is the low economic potential or ROI available with skin disease treatments which inhibits the creation of novel therapies for dermatologic disease.

Markedly elevated serum lactate dehydrogenase levels are a clue to the diagnosis of disseminated histoplasmosis in patients with AIDS.

Disseminated histoplasmosis is a common late manifestation of AIDS, but the diagnosis may be unsuspected in some patients because the clinical presentation of histoplasmosis may mimic other opportunistic infections. High serum lactate dehydrogenase (LDH) levels have been associated with disseminated histoplasmosis. We therefore evaluated whether markedly increased LDH levels were useful for making a diagnosis of disseminated histoplasmosis by comparing admission LDH levels for 15 patients with culture-proven disseminated histoplasmosis with those for 30 patients with advanced AIDS who were admitted to the hospital for evaluation of pulmonary infiltrates and fever. The mean admission LDH level in patients with disseminated histoplasmosis was 1,356 IU/L (range, 145-5,410 IU) whereas it was 332 (range, 77-832 IU) in the patients with other pulmonary processes. Admission LDH levels were >600 IU in 11 (73%) of the 15 patients with disseminated histoplasmosis vs. 3 (10%) of controls (P < .001). We conclude that markedly elevated admission LDH levels may be a clinical clue to the diagnosis of disseminated histoplasmosis in patients with AIDS.