DermNet® Merkel cell carcinoma

·Merkel cell carcinoma has an estimated incidence of per 100 000 people in Caucasian populations which is much less common than melanoma Increasing numbers of Merkel cell carcinomas have been reported by some centres in recent years Merkel cell carcinoma mainly affects older people with most cases occurring after the …

DermNet® ABCDEFG of melanoma

Border irregularity B is for Border A melanocytic naevus has smooth even borders whereas a melanoma often has irregular blurry or jagged edges and hard to define On careful inspection the pigmented component of a flat melanocytic naevus fades out towards the edge whereas the edges of a solar lentigo or a seborrhoeic …

Stevens Johnson syndrome / toxic epidermal necrolysis

·Stevens Johnson syndrome SJS and toxic epidermal necrolysis TEN are now believed to be variants of the same condition distinct from erythema multiforme SJS/TEN is a rare acute serious and potentially fatal skin reaction in which there are sheet like skin and mucosal loss Using current definitions it is nearly always caused by

DermNet® Granuloma

Histopathology of granulomas A granuloma is a chronic inflammatory pattern characterised by the localised aggregation of histiocytes with or without other inflammatory cells eg plasma cells eosinophils neutrophils with or without necrosis with or without vasculitis with or without calcification with or without foreign bodies

DermNet® Systemic lupus erythematosus SLE

Lupus erythematosus LE is a group of diverse persistent autoimmune inflammatory diseases Systemic lupus erythematosus SLE affects several organs such as skin joints and kidneys and blood tests reveal circulating autoantibodies The clinical features of SLE are highly variable and may overlap with other diseases and conditions

DermNet® Methotrexate

What is methotrexate Methotrexate is a medication used in low doses to treat inflammatory skin conditions such as psoriasis and eczema/ is also prescribed for rheumatoid arthritis psoriatic arthritis and increasingly other inflammatory and autoimmune disorders off label In much higher doses it is used as a chemotherapy agent for leukaemia and …

DermNet® Lyme disease Borrelia burgdorferi infection

Lyme disease is an infection caused by Borrelia a type of bacteria called a spirochaete Lyme disease can affect any part of the body most commonly the skin central nervous system joints heart and rarely the eyes and liver Lyme disease is common in parts of the United States particularly in Massachusetts and Europe but is reported from

DermNet® Cherry Angioma Features Causes and Removal — DermNet

Cherry angioma is an asymptomatic firm red blue or purple papule 1 cm in diameter When thrombosed it can appear black in colour until examined with a dermatoscope when the red or purple colour is more easily seen Cherry angiomas are usually multiple They are usually scattered over any part of the body surface but are rarely found

DermNet® Brown spots lentigos and freckles

Brown spots and freckles on sun exposed skin are ephelides the plural of ephelis and lentigines the plural of lentigo The difference between an ephelis and a lentigo is that an ephelis fades during the winter months while a lentigo persists in the absence of ultraviolet UV stimulation Ephelides and lentigines can occur in the same

DermNet® Hidradenitis Suppurativa Acne Inversa A …

Hidradenitis suppurativa HS also called acne inversa is a chronic inflammatory skin condition that affects apocrine gland bearing skin in the axillae groin and under the breasts It is characterised by persistent or recurrent boil like nodules and abscesses that culminate in a purulent discharge sinuses and scarring

DermNet® Malassezia pityrosporum folliculitis

Topical steroids are the mainstay treatment for mild to moderate atopic dermatitis They are safe and effective when used correctly The strength of a topical steroid is determined by the structure of the molecule The weakest steroid used for the shortest time to be effective is usually prescribed

DermNet® Risankizumab

Risankizumab is an interleukin IL 23 antagonist indicated for the treatment of moderate to severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy [1] Risankizumab was approved by the US Food and Drug Administration FDA in April 2019 in Japan in March 2019 and by the European Union in March 2019

DermNet® Asteatotic Eczema Eczema Craquelé — DermNet

Asteatotic eczema is a common type of dermatitis that occurs as a result of dry skin It got its French name eczema craquelé from its cracked appearance It is also known as xerotic dry eczema The most common site is the shins but asteatotic eczema may occur elsewhere including upper limbs and trunk

DermNet® Dermatitis Nummular dermatitis

Nummular dermatitis or eczema is also known as discoid eczema or dermatitis It has two forms Exudative wet nummular dermatitis Dry nummular dermatitis Exudative nummular dermatitis The exudative variant starts acutely and may persist for weeks months and rarely years Although it may arise at any age most subjects are over 50

DermNet® Female pattern hair loss

Female pattern hair loss FPHL is a distinctive form of diffuse hair loss that occurs in women with androgenetic alopecia Many women are affected by FPHL Around 40% of women by age 50 show signs of hair loss and less than 45% of women reach the age of 80 with a full head of hair In FPHL there is diffuse thinning of hair on the scalp due to

DermNet® Guidelines for the management of adult eczema

Avoid use of soaps and detergents Keep fingernails short Keep skin hydrated Eczema is characterised by reduced skin barrier function which leads to enhanced water loss and dry skin therefore hydrate with warm soaking baths for at least 10 minutes followed by application of moisturiser/ emollient

DermNet® Scabies test

Scabies is a transmissible skin disease caused by the ectoparasitic mite Sarcoptes scabiei var hominis This variant infests humans only; scabies cannot be caught or transferred to other animals Scabies is a highly contagious infestation of the human epidermis Scabies was described by Aristotle who likened the disease to lice of the flesh

DermNet® Melanoma in situ

Melanoma in situ is an early form of primary melanoma in which the malignant cells are confined to the tissue of origin the epidermis It is also known as in situ melanoma and level 1 melanoma As melanoma in situ has no associated mortality early detection of melanoma in an in situ phase increases survival from melanoma and leads to less

DermNet® Fixed drug eruption

Fixed drug eruption is a delayed type IV hypersensitivity reaction In the initial phase memory CD8 T cells at the dermo epidermal junction release interferon gamma when activated by the medication antigen causing epidermal basal layer damage Recruited T cells and neutrophils damage melanocytes and keratinocytes

قطران تعرف على انواعه، وفوائده الطبية

يوجد العديد من الخصائص التي تميز قطران الفحم، فهو غير قابل للذوبان، وتتراوح درجة غليانه بين 200 250 درجة مئوية، وله كثافته سميكة جداً وله رائحة غريبة، ويستخدم قطران الفحم في تصنيع الدهانات والأصباغ الاصطناعية

DermNet® Napkin dermatitis Diaper rash Nappy rash

Napkin dermatitis presents as erythematous macules and papules in the genital area that can spread to involve the lower abdomen and thighs Irritant napkin dermatitis well demarcated variable erythema oedema dryness and scaling Affected skin is in contact with the wet napkin and tends to spare the skin folds

DermNet® Flea bites

A flea has three pairs of legs with long hind legs ideal for jumping They are wingless They can jump up to 18 cm in height Adult fleas of domestic animals tend to live on the animal for easy access to blood meals The female fleas lay white round eggs that tend to fall off the animal onto bedding floor and soil

DermNet® Staphylococcal skin infections

A staphylococcal infection is a common bacterial skin infection Staphylococci staph are a common type of bacteria that live on the skin and mucous membranes for example in the nostrils of humans Staphylococcus aureus S aureus is the most important of these bacteria in human diseases Other staphylococci including S epidermidis