Pityriasis rosea is a type of skin rash. Classically, it begins with a single red and slightly scaly area known as a "herald patch". This is then followed, days to weeks later, by an eruption of many smaller scaly spots; pinkish with a red edge in people with light skin and greyish in darker skin. About 20% of cases show atypical deviations from this pattern. It usually lasts less than three months and goes away without treatment. Sometimes malaise or a fever may occur before the start of the rash or itchiness, but often there are few other symptoms.
Purpura is a condition of red or purple discolored spots on the skin that do not blanch on applying pressure. The spots are caused by bleeding underneath the skin secondary to platelet disorders, vascular disorders, coagulation disorders, or other causes. They measure 3–10 mm, whereas petechiae measure less than 3 mm, and ecchymoses greater than 1 cm.
Incontinentia pigmenti (IP) is a rare X-linked dominant genetic disorder that affects the skin, hair, teeth, nails and central nervous system. It is named from its appearance under a microscope.
Sweet syndrome (SS), or acute febrile neutrophilic dermatosis, is a skin disease characterized by the sudden onset of fever, an elevated white blood cell count, and tender, red, well-demarcated papules and plaques that show dense infiltrates by neutrophil granulocytes on histologic examination.
Schamberg's disease, is a chronic discoloration of the skin found in people of all ages, usually only affecting the feet, legs or thighs or a combination. It may occur as a single event or subsequent bouts may cause further spread. It is most common in males. It is named after Jay Frank Schamberg, who described it in 1901. There is no known cure for this disease but it is not a life-threatening condition and is mainly of cosmetic concern, although, because it can appear so suddenly, so extensively and because it usually leaves permanent discoloration of the skin, it can cause understandable psychological concern. The skin lesions sometimes cause itching, which can be treated by applying cortisone cream. The cortisone cream will only help with the itching and does not improve the discoloration of the skin. Schamberg's disease causes no other symptoms beside skin discoloration and itching. The condition is caused by inflammation of capillaries near the surface of skin and subsequent leaking of red blood cells into surrounding tissues. As the red blood cells break down and get mostly resorbed, some of the iron released by the red blood cells remains in the skin and causes the characteristic rust-colored appearance. The cause of the capillary inflammation is usually unknown.
Gianotti–Crosti syndrome, also known as infantile papular acrodermatitis, papular acrodermatitis of childhood, and papulovesicular acrolocated syndrome, is a reaction of the skin to a viral infection. Hepatitis B virus and Epstein–Barr virus are the most frequently reported pathogens. Other viruses implicated are hepatitis A virus, hepatitis C virus, cytomegalovirus, coxsackievirus, adenovirus, enterovirus, rotavirus, rubella virus, HIV, and parainfluenza virus.
Capillaritis is where the capillaries, usually of the legs or lungs, are inflamed, allowing blood cells to pass through.
Neutrophilic eccrine hidradenitis (NEH) usually is a cutaneous complication of chemotherapy, but it can also occur for other reasons. It consists of fever and non specific skin lesions. It is rare, and self-limited.
Transient neonatal pustular melanosis (TNPM), also known as pustular melanosis, is a transient rash common in newborns. It is vesiculopustular and made up of 1–3 mm fluid-filled lesions that rupture, leaving behind a collarette of scale and a brown macule.[3] This rash occurs only in the newborn stage, usually appearing a few days after birth[2], but is sometimes already present at birth[3]. The rash usually fades over three to four weeks but may linger for up to three months after birth.[3] It can occur anywhere on the body, including the palms and soles.[1][2][3]
Solar purpura is a skin condition characterized by large, sharply outlined, 1- to 5-cm, dark purplish-red ecchymoses appearing on the dorsa of the forearms and less often the hands.
Orthostatic purpura is a skin condition that results from prolonged standing or even sitting with the legs lowered, which produced edema and a purpuric eruption on the lower extremities.
Painful bruising syndrome is an idiopathic trauma-induced condition seen in young to middle-aged women who sometimes manifest personality disorders. It is characterized by a distinctive localized purpuric reaction occurring primarily on the legs, face and trunk, with recurring painful ecchymoses variably accompanied by syncope, nausea, vomiting, gastrointestinal and intracranial bleeding.
Majocchi's disease, also known as Purpura annularis telangiectodes of Majocchi is a not-well-recognized and uncommon skin condition characterized by purple/bluish-red 1- to 3-cm annular patches composed of dark red telangiectases with petechiae. It is one of a group of disorders referred to as pigmented purpuric dermatosis that all occur as a result of vascular inflammation and pigment deposition.
Gougerot–Blum syndrome is a variant of pigmented purpuric dermatitis, a skin condition characterized by minute, rust-colored to violaceous, lichenoid papules that tend to fuse into plaques of various hues. Relative to other variants, it is characterized clinically by a male predominance, pruritus, with a predilection for the legs, and histologically, it features a densely cellular lichenoid infiltrate.
Doucas and Kapetanakis pigmented purpura is a skin condition characterized by scaly and eczematous patches, which also have petechiae and hemosiderin staining.
Lichen aureus is a skin condition characterized by the sudden appearance of one or several golden or rust-colored, closely packed macules or lichenoid papules.
Cutaneous small-vessel vasculitis (CSVV), also known as hypersensitivity vasculitis, cutaneous leukocytoclastic vasculitis, hypersensitivity angiitis, cutaneous leukocytoclastic angiitis, cutaneous necrotizing vasculitis and cutaneous necrotizing venulitis, is inflammation of small blood vessels, characterized by palpable purpura. It is the most common vasculitis seen in clinical practice.
Domenico Majocchi (1849–1929) was an Italian dermatologist ,an histologist and anatomo-pathologist of great value and an extremely expert clinician, who discovered some pathologies such as the purpura annularis telangiectodes and the Fungal folliculitis.
Histopathology of dermatitis can be performed in uncertain cases of inflammatory skin condition that remain uncertain after history and physical examination.
