Cromoglicate in Mastocytosis

Inclusion Criteria:

* Signed informed consent has been obtained
* Chronic stable symptomatic maculopapulous cutaneous mastocytosis or indolent systemic mastocytosis with skin involvement and a positive Darier's Sign
* Age between 18 and 70 years
* Either sex
* Any race or ethnicity
* Attending hospital outpatient clinic or the private practice of a dermatologist.

Exclusion Criteria:

* The presence of autoimmune and infectious disease including aggressive systemic mastocytosis
* Medical history or presence of epilepsy, significant neurological disorders, cerebrovascular attacks or ischemia
* Medical history or presence of myocardial infarction or cardiac arrhythmia which requires drug therapy, hyper/hypokalemia
* Evidence of severe renal dysfunction (creatinine \> 1,5 times upper reference value)
* Evidence of significant hepatic disease (liver enzymes \> 2 times upper reference value)
* Presence of active cancer which requires chemotherapy or radiation therapy
* Commitment to an institution in terms of § 40 Abs. 1 S. 3 Nr. 4 AMG
* Intake of antihistamines or leukotriene antagonists within 7 days prior to the beginning of the study
* Intake of oral corticosteroids within 14 days prior to randomisation
* Use of depot corticosteroids or chronic systemic corticosteroids within 21 days prior to randomisation
* Radiation therapy of target areas including UV therapy within 4 weeks prior to randomisation
* Confounding other dermatological diseases or conditions that can affect the symptoms of the target areas
* Known or suspected hypersensitivity to component(s) of investigational products.
* Current participation in any other interventional clinical trial.
* Subjects who have received treatment with any nonmarketed drug substance (i.e. an agent which has not yet been made available for clinical use following registration) within the last 4 weeks or 5 half-lives (whichever is longer) prior to randomisation
* Previously randomised in this clinical trial
* In the opinion of the investigator, the subject is unlikely to comply with the Clinical Study Protocol (e.g. alcoholism, drug dependency or psychotic state).
* Females who are pregnant, of child-bearing potential and wishing to become pregnant during the trial or are breast feeding.
* Females of child-bearing potential with positive pregnancy test at visit 1.
* Subjects (or their partner) not using an adequate method of contraception (according to national requirements, as applicable)