TAMS is developing a new information series to be shared on the TAMS website and via our Facebook page and patient group. It will detail the various diagnoses of Mast Cell Disease. Our second Explaining Mast Cell Disease info sheet and post focus on Adult Onset Cutaneous Mastocytosis (download the Adult Onset Cutaneous Mastocytosis info sheet).
Adult Onset Cutaneous Mastocytosis
Adult onset cutaneous mastocytosis is very persistent and often leads to a diagnosis of systemic mastocytosis. Around 90% of adults with cutaneous mastocytosis will progress to a diagnosis of systemic mastocytosis. However not all adults diagnosed with systemic mastocytosis will present with cutaneous mastocytosis.
Maculopapular cutaneous mastocytosis is the most common form of cutaneous disease in adults, with a diagnosis of another variant being much rarer. Adults with this diagnosis can experience systemic symptoms due to release of mediators from mast cells in the skin.
Dermatology is the main medical specialty to diagnose cutaneous mastocytosis. Generally, for adults, a skin biopsy is performed to confirm the diagnosis.
The main forms of cutaneous mastocytosis are:
Maculopapular Cutaneous Mastocytosis
Maculopapular cutaneous mastocytosis was previously called urticaria pigmentosa. It is the most common form of mastocytosis in adults and children and is characterised by itchy, red/brown patches on the skin. Initially these patches can resemble freckles or insect bites and may gradually increase in number over time.
Solitary cutaneous mastocytoma is a localised form of cutaneous mastocytosis and is typically diagnosed in young children. It is characterised by an itchy area of reddish or brown patch of skin that is often thickened.
This form of cutaneous mastocytosis appears to resolve spontaneously with age and is rarely diagnosed in adults.
Diffuse Cutaneous Mastocytosis
Diffuse cutaneous mastocytosis usually develops in infancy and affects most or all of the skin. It typically presents as diffuse redness of the skin (erythrodema), sometimes with widespread blistering. In people affected by this condition, the skin appears leathery and thickened with a positive Darier sign (redness of skin after being stroked). Additional symptoms may include diarrhoea, flushing (reddening) of the skin, and anaphylactic shock.
Telangiectatic Cutaneous Mastocytosis
Telangiectatic cutaneous mastocytosis, also known as Telangiectasia Macularis Eruptiva Perstans (TMEP), is primarily diagnosed in adults and is generally not associated with blistering. This is a rare form of cutaneous mastocytosis in adults and has therefore become part of the Maculopapular Cutaneous Mastocytosis classification.