Chronic Widespread Pain and White Blood Cell Activation

Inclusion Criteria: * Female and male adolescents aged between 14 to 18 years old; * For female adolescents of child bearing potential: negative serum pregnancy test at base line screening; * For female adolescents of child bearing potential: being willing and able to use contraceptive methods for the duration of the study and for 30 days after receiving the last dose of the study drug; * Diffuse body pain that has been present for at least 3 months, and who also have symptoms of fatigue, sleep disturbance, cognitive changes and mood disorder; * Accompanied by at least one somatic symptoms to variable degree including irritable bowel syndrome, headaches, menstrual pain, lower urinary tract symptoms, myofascial pain, and temporomandibular pain; * Symptoms cannot be explained by some other illness; * Physical examination which should be within normal limits except for tenderness on pressure of soft tissues (i.e. tactile hyperalgesia which is increased pain following a painful stimulus) * Overall body pain average score ≥ 4 * Moderate to severe physical impairment Functional Disability Inventory \> 12 points. * Stable doses of his/her current medication for at least four weeks * Not having significant changes in their health conditions (PIGS less than 6 points) after 8 weeks of treatment Exclusion Criteria: * Be part of other trials; * Have a specific diagnosis that can explain the symptoms; including rheumatoid arthritis, systemic lupus erythematosus, scleroderma and/or other connective tissue diseases * Refuse to donate blood sample; * Not be able to fill electronic records; * Cognitive impairment interfering with the clinical evaluations; * Known intolerance or allergies to KF; * Been under treatment with other mast cell stabilizer agent; * Seizures history or actual treatment; * Coagulopathies or chronic thrombocytopenia; * Atopic dermatitis (eczema) or chronic urticaria (hives) * Schizophrenia or bipolar disorder * Elective surgery within the study timeline * Abnormal labs results (i.e., elevated SGPT and low platelet count, low Hb or Ht) in the last 6 months or in the base line evaluation * Patients who are pregnant or are breast-feeding; * Patients who are on oral antidiabetic agents;