Unusual Milk Colors

Clofazimine

Clofazimine is a deep red-colored drug used to treat leprosy. Milk can reportedly be colored pink by the drug. Because of the high lipid solubility of the drug, it can deposit in the skin of infants fed with this milk. The tissue half-life is about 70 days, so the infant's skin can be colored the typical red to bronze color that is common in persons taking the drug. No serious or permanent toxicity has been reported in affected infants, and the skin color fades 3–5 months after the end of breastfeeding or maternal therapy.

Rifamycins

Rifampin, rifabutin, and rifapentine are also red compounds that are known to color various bodily secretions pink to red, including tears, which can permanently stain contact lenses. Only the rifapentine product information mentions that milk might also be colored pink, although apparently no cases have been reported. In the only published case, the mother was taking rifampin and clofazimine, and the infant developed the red skin discoloration of clofazimine noted above.

Iron

Two cases implicate iron as a rare cause of green milk. One was in a mother heterozygous for thalassemia who took an oral ferritin preparation containing 78.6 mg of iron daily during pregnancy for anemia. The iron from disease-related hemolysis and exogenous ferritin apparently was reduced to ferrous iron, which can have a pale green color. Another case of green breast milk was reported in a woman who took a high-potency vitamin–mineral supplement containing 17 mg of iron during two pregnancies. In each case, it took 3–4 weeks after discontinuation of the multivitamin–mineral product for the color of milk to return to normal.^1,2

Blood

Blood can enter the milk from more than one site. Blood from cracked nipples or the areola can impart a pink or red color to the milk. Perhaps more alarming is the so-called rusty-pipe syndrome, which causes a dark brownish-red color of milk. It is thought that this is caused by the rupture of capillaries deeper in the breast. In one case, the hematocrit of breast milk was found to be 14%. The syndrome is usually only noticed if the mother is expressing milk and not feeding at the breast. The milk color usually clears in 3–7 days.^3–5

Minocycline

Minocycline is notorious for causing black discoloration of various tissues. It causes a black pigmentation in various places such as the bones, eyes, thyroid, and mucous membranes. ⁶ Two cases of black milk have been reported, one in a nursing mother after taking the drug for about 3–4 weeks and the other in a non-nursing woman who developed galactorrhea while taking minocycline for over 4 years, plus perphenazine, amitriptyline, and diphenhydramine. In both of these cases, macrophages containing a black iron-containing pigment were found in milk. It is thought that the pigment is an iron chelate of minocycline or one of its metabolites. In the nursing mother, milk iron levels were over 100 times greater than normal. The absorption of the iron by the infant is not known.

Propofol

A woman underwent emergency laparoscopic surgery using propofol, as well as fentanyl, remifentanil, mivacurium, and dipyrone (metamizole) during the surgery and dipyrone, piritramide (a synthetic opioid), butylscopolamine, and metoclopramide postoperatively. Eight hours postoperatively, her milk turned bluish green, then green. Both propofol and metoclopramide have caused green urine. Thirty hours after the milk color change, propofol, but not metoclopramide, was detected in milk. The color disappeared by 48 hours postoperatively.

Foods

Sources often attribute coloration of breast milk to foods the mothers have eaten, such as green color from green vegetables or pink milk from beets. But virtually no good documentation of food-induced coloration of milk exists. Beta-carotene and other carotenoids in milk are well documented to be related to dietary intake and are said to be the cause of the orange color of colostrum and the pale white to cream coloration of mature milk. Although no cases of frankly orange milk have been reported, one case of orange skin coloration in a breastfed infant was reported. The infant's mother was eating 2–3 pounds of carrots weekly.

A case of spirulina-induced breast milk discoloration was reported to the Australian Therapeutic Goods Administration (analogous to the U.S. Food and Drug Administration). Neither the specific product, amount ingested, nor color was reported, but presumably this blue-green algae could impart a greenish color to the milk. Kelp and other dietary supplements also reportedly caused greenish breast milk in some women, although details are lacking.^11–13

Artificial Colors

One exclusively breastfed infant developed pink urine each time her mother drank Sunkist orange drink that contained the artificial colors, FD&C yellow #6 and red #40. Although the color of the mother's milk was not mentioned, it appears that at least the red dye was able to enter the milk. The green color of Gatorade has reportedly caused green milk coloration.^13,14

Table 1 summarizes the information reported in this column, sorted by color.