Vaccines in Dermatology.

A vaccine is a biological preparation that improves immunity to a specific disease. More than two centuries have passed since the first successful vaccine for smallpox was developed. We've come a long way since.

Eccrine poroma on the face: an atypical presentation.

An eccrine poroma is a solitary tumor arising from the eccrine duct epithelium in the epidermis. The lesions commonly occur on the sole of the foot, the hands, and occasionally on the nose, eyelids, neck, and chest. We report a patient who presented with a slow-growing nodular lesion over her left cheek, prompting a diagnosis of basal cell carcinoma or keratoacanthoma.

Multicentric reticulohistiocytosis.

Multicentric reticulohistiocytosis is a rare systemic granulomatous disease of an unknown cause, characterized by distinct histopathology. The skin, mucosa, synovial, bone, and internal organs may be involved. Cutaneous nodules and distinctive arthritis are the most prominent clinical features.

Diffuse cutaneous leishmaniasis: co-infection with human immunodeficiency virus (HIV).

Cutaneous leishmaniasis is a disease caused by intracellular protozoal parasites belonging to the genus Leishmania. Immune suppression caused by HIV infection is an important factor for atypical presentation and widespread progression of cutaneous leishmaniasis. Diffuse (disseminated) cutaneous leishmaniasis and HIV co-infection is emerging as an extremely serious new disease.