Nummular psoriasis is a form of psoriasis which is often lesser known to the general public.
Summary
Psoriasis is a chronic inflammatory skin disease, which as it develops, alternates between flare-up and remission phases. During the flare-up phases, also known as outbreaks, plaques appear on one or several areas of the body. However, it would be more accurate to talk about "types of psoriasis" rather than simply "psoriasis" because it can take so many different forms.
Nummular psoriasis, one of these other types, is not that well known among the general public, probably because it is less common than plaque psoriasis and the lesions are smaller in size. Nummular psoriasis is characterized by round lesions whose size and shape resemble spots or coins, hence the term "nummular". Where these plaques appear on the body varies widely from patient to patient: however, some areas are more common than others, such as the limbs (arms and legs). Nummular psoriasis plaques are highly inflammatory and the itching they cause is often very intense. Other forms of psoriasis can occur in conjunction with nummular psoriasis, such as nail, scalp or joint psoriasis, etc.
The rounded shape of the plaques associated with nummular psoriasis is sometimes indicative of certain fungal infections. In case of doubt, a sample is taken from the lesion to check if fungi are present. Another skin disease with a similar name is sometimes confused with nummular psoriasis: nummular eczema, which involves the formation of small, rounded plaques. However, these plaques are likely to ooze and form scabs, which is not the case with psoriasis.
Nummular psoriasis is treated using the same treatments as plaque psoriasis: creams, tablets, injections or even phototherapy, depending on the case.
