What are the signs and symptoms of Cutaneous mastocytosis? Cutaneous mastocytosis is a form of mastocytosis that primarily affects the skin. There are three main forms that vary in severity: maculopapular cutaneous mastocytosis (also called urticaria pigmentosa), solitary cutaneous mastocytoma, and diffuse cutaneous mastocytosis. There is also an exteremely rare form called telangiectasia macularis eruptiva perstans. Maculopapular cutaneous mastocytosis, the most common form of cutaneous mastocytosis, is characterized by itchy, brown patches on the skin. Although these patches may be mistaken for freckles or bug bites initially, they typically persist and gradually increase in number over several months to years. In young children, the patches may form a blister if itched or rubbed. Itching may worsen with changes in temperature, strenuous activity, emotional stress, and/or certain medications. Maculopapular cutaneous mastocytosis is most commonly seen in infants and young children and often fades by the teenaged years. In some cases, this condition may not develop until adulthood. These later onset cases generally last long-term and are more likely to progress to systemic mastocytosis. Solitary cutaneous mastocytoma is a localized form of cutaneous mastocytosis. Like maculopapular cutaneous mastocytosis, this form is typically diagnosed in young children. However, it is characterized by an itchy area of reddish or brown skin that is often thickened. When itched, these patches of skin may swell, redden, and/or blister. This form typically resolves spontaneously with age. Diffuse cutaneous mastocytosis, the most severe form of cutaneous mastocytosis, usually develops in infancy. Unlike the other forms of cutaneous mastocytosis, it affects most or all of the skin rather than appearing as distinct patches. In people affected by this condition, the skin is leathery and thickened. It may appear normal, yellowish-brown, or red in color. In some cases, there may also be widespread blistering. Additional symptoms may include hypotension, diarrhea, gastrointestinal bleeding, reddening of the skin (flushing), and anaphylactic shock. The rarest form of cutaneous mastocytosis is called telangiectasia macularis eruptiva perstans. Unlike the other forms of cutaneous mastocytosis, this form is primarily diagnosed in adults and is generally not associated with pruritus and blistering. People affected by this condition have persistent brown patches of skin and extensive telegiactasia. Rarely, this form may progress to systemic mastocytosis. The Human Phenotype Ontology provides the following list of signs and symptoms for Cutaneous mastocytosis. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Hypermelanotic macule 90% Mastocytosis 90% Pruritus 90% Urticaria 90% Abdominal pain 50% Abnormal blistering of the skin 50% Abnormal renal physiology 7.5% Asthma 7.5% Behavioral abnormality 7.5% Coronary artery disease 7.5% Diarrhea 7.5% Gastrointestinal hemorrhage 7.5% Hepatomegaly 7.5% Hypercalcemia 7.5% Hypotension 7.5% Impaired temperature sensation 7.5% Increased bone mineral density 7.5% Leukemia 7.5% Malabsorption 7.5% Migraine 7.5% Nausea and vomiting 7.5% Recurrent fractures 7.5% Reduced bone mineral density 7.5% Respiratory insufficiency 7.5% Sarcoma 7.5% Splenomegaly 7.5% Sudden cardiac death 7.5% Telangiectasia of the skin 7.5% The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.