Milk ladders

The milk ladder is a step wise process to reintroducing milk back into the diet for those diagnosed with Cow's Milk Allergy (CMA). It starts with foods that have been extensively heated through baking, denaturing the protein and therefore less likely to trigger an allergic response.

Casein and whey are the main milk proteins that cause allergic reactions. Casein is a linear epitope meaning it is heat resistant, whereas whey proteins have a confirmational structure meaning it is heat liable and more likely to be tolerated¹. Studies have also shown that when milk proteins are mixed in a wheat matrix (such as wheat flour) they are also more likely to be tolerated².

The milk ladder was initially intended for those diagnosed with mild to moderate non-IgE mediated CMA³. More recently it has been shown to be successful in IgE mediated CMA after appropriate review with an allergy team to ensure it is safe to conduct at home^4,5. This is a much slower process compared to the milk ladder used in non-IgE mediated CMA and only healthcare professionals (HCPs) with the right competencies should advise this approach and the risks involved. 

There have been several different milk ladders published, including the 4 step, 6 step and 12 step ladders ^3,6,7, and so it can be confusing for both HCPs and parents to know which one to follow. A recent paper highlighted the need for standardisation across the ladders as many HCPs use different or adapted versions¹.

The first milk ladder to be published in the UK was the 12-step milk ladder from the ‘Managing Allergy in Primary Care’ guideline⁷. More recently, this has been updated to a 6-step milk ladder (IMAP) and is an international guideline due to the MAP resource being assessed and regularly downloaded worldwide³. It was also updated based on new research, as well as families expressing concerns regarding ‘unhealthy’ food options on the 12-step ladder which was rectified with homemade recipes on the 6 step ladder⁸. 

Before starting the milk ladder, it is important to ensure that the child is well and that any gastrointestinal or skin symptoms such as eczema are settled and under control. It is best to start earlier in the day so that if there are to be symptoms these can be monitored throughout the day.

One study highlighted that the main concerns families expressed with the milk ladder is how to recognise potential symptoms as well how much time to spend at each step⁸. 

Most children will start at step 1 unless they have had steps higher on the milk ladder and tolerated. Knowing when to start will be dependent on each child and their previous history and symptoms. The IMAP guideline advises to start at around 9-12 months or after a period of 6 months of avoiding milk. There is now some research to suggest starting the ladder earlier, from diagnosis, rather than waiting 6 months⁵.

The first 3 steps on the milk ladder are designed to be used with homemade recipes; this is to ensure that each step has the appropriate milk intake. There are shop bought alternatives, although it is difficult to know exactly how much milk protein they contain as shop bought alternatives can change their recipes and amounts of milk protein - this will also change from one brand to another.

For example, when comparing the IMAP biscuit recipe and a malted milk biscuit (step 1), a malted milk contains around ~0.023-0.043g of milk protein⁴ and one IMAP biscuit contains 0.035g of milk protein. Shop bought alternatives will also contain other ingredients such as sugar and salt. It is, therefore, important to advise families to be mindful of this in line WHO recommendations for <5% of total energy intake from refined sugars¹.

If a child is tolerating step 3 (pancakes), then shop bought alternatives such as plain muffins, scones, croissants, brioche, pastry and bread can be included as maintaining certain steps for long periods can cause taste fatigue. Offering different foods containing milk will also aid in building on variety. 

On each step of the milk ladder there are suggested portion sizes which are just a guide. In some cases, it may be advisable to start with smaller amounts such as ¼ or ½ portions depending on the child’s previous history and symptoms.

This is also the case for the time spent on the ladder. Some children may progress on a step quickly (within a week), others may stay on a step for a few months. If a child does react, simply advise to go back to the previous step, and continue to keep previous steps in the diet. It is up to the managing HCP to decide when to trial again. 

Each of the recipes have soya, egg and wheat free options for those with multiple allergies. The recipes can easily be adapted to include in other recipes as long as the milk protein, portion sizes and temperature of cooking remain the same. For example, on step 2 (muffin) the same recipe could be used for scones.