As Papel ( papula of latin, bubbles ') or nodules is called in medicine up to pea-sized raised thickening of the skin. It is one of the primary lesions ( predominant primary ) and can completely regress without scarring. Stove -shaped confluent ( confluent ) papules are called plaques. The formation of papules can be caused by various skin diseases. Triggers can be insect bites, bacterial infections, dermatophytosis, protozoa ( Leishmania ), parasites (scabies, sarcoptic mange ), allergies or skin tumors.
After the localization in the layers of the skin following forms are distinguished:
- The epidermal papule is a proliferation of cells in the stratum ( stratum corneum) or squamous cell layer (stratum spinosum ) of the epidermis. The epidermal papule may consist of normal skin cells (eg, a wart ), there are tumor cells ( epithelial lymphoma) or inflammatory cells ( leukocytes). Inflammatory papules are red and can evolve into pustules.
- The cutaneous papule is a proliferation of cells of the dermis ( corium ) as occurs for example in secondary syphilis or nevus.
- Epidermophyton papule the cutaneous form, the mixing in which cells proliferate in both the epidermis and dermis. Epidermophyton cutaneous papules are, for example eczema or lichen planus before.