No special blood tests or diagnostic procedures are usually required to make the diagnosis.The differential diagnosis of psoriasis includes dermatological conditions similar in appearance such as discoid eczema, seborrheic eczema, pityriasis rosea (may be confused with guttate psoriasis), nail fungus (may be confused with nail psoriasis) or cutaneous T cell lymphoma (50% of individuals with this cancer are initially misdiagnosed with psoriasis). Dermatologic manifestations of systemic illnesses such as the rash of secondary syphilis may also be confused with psoriasis.If the clinical diagnosis is uncertain, a skin biopsy or scraping may be performed to rule out other disorders and to confirm the diagnosis. Skin from a biopsy shows clubbed epidermal projections that interdigitate with dermis on microscopy. Epidermal thickening is another characteristic histologic finding of psoriasis lesions. The stratum granulosum layer of the epidermis is often missing or significantly decreased in psoriatic lesions; the skin cells from the most superficial layer of skin are also abnormal as they never fully mature. Unlike their mature counterparts, these superficial cells keep their nuclei. Inflammatory infiltrates can typically be seen on microscopy when examining skin tissue or joint tissue affected by psoriasis. Epidermal skin tissue affected by psoriatic inflammation often has many CD8+ T cells, while a predominance of CD4+ T cells makes up the inflammatory infiltrates of the dermal layer of skin and the joints. Classification
Morphological
Psoriasis is classified as a papulosquamous disorder and is most commonly subdivided into different categories based on histological characteristics. Variants include plaque, pustular, guttate, and flexural psoriasis.
Tepotinib, sold under the brand name Tepmetko, is a medication used for the treatment of adults with non-small cell lung cancer (NSCLC).Tepotinib first received marketing approval in Japan, in March 2020, as a "line-agnostic" drug, meaning it is approved both for treatment-naive patients and for those in whom previous attempts at treatment have failed. U.S. approval followed in February 2021. It is the second therapy approved by the U.S. Food and Drug Administration (FDA) to treat non-small cell lung cancer with these particular mutations, after capmatinib. Medical uses
Tepotinib is indicated for the treatment of adults with metastatic non-small cell lung cancer (NSCLC) whose tumors have a mutation that leads to mesenchymal-epithelial transition (MET) exon 14 skipping. Adverse effects
The most common side effects seen in clinical trials were edema, fatigue, nausea, diarrhea, muscle aches, and shortness of breath. Like capmatinib, tepotinib can also cause interstitial lung disease and liver damage, and is toxic to a developing fetus. The most common treatment-related adverse effect in a 2021 study were peripheral edema (54.1%), nausea (20.0%), diarrhea (19.6%), blood creatinine increased (17.6%), and hypoalbuminemia (14.5%), which were mostly mild or moderate. Society and culture
Legal status
On 16 December 2021, the Committee for Medicinal Products for Human Use (CHMP)  of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Tepmetko, intended for the treatment of patients with advanced non-small cell lung cancer (NSCLC) harboring alterations leading to mesenchymal-epithelial transition factor gene exon 14 (METex14) skipping.