Diagnosis is made by history, appearance of the skin and tongue examination. The etiology of atopic dermatitis according to TCM is closely related with the condition and function of the internal (zang/fu) organs. Lack of appetite is the most common spleen disharmony according to classical TCM pattern differentiation. The impairment of the spleen transformation and transportation function causes the various digestive symptoms which can give rise to the retention of dampness. As the parents of the patient reported him eating far less than the amount suggested by pediatrician according to age, height and weight the patient’s small appetite indicated toward spleen deficiency. 

The appearance of rash on the patient’s skin also indicated the possibility of retention of dampness in the skin. The contribution of tongue diagnosis had several distinctions which made its importance in this case. According to tongue diagnosis in TCM: the tongue almost always reflects the true condition of the patient; the tongue appearance is a most useful gauge for monitoring the improvement or decline of the patient’s condition; the topography of the tongue (correspondence of different areas of the tongue to different organs) is a subject of fairly general agreement; tongue diagnosis is relatively objective in comparison with other techniques, such as the different interpretations over pulse characteristics.

The patient’s initial tongue coating was found to be white and thick with slight visible tongue edges. Due to the small size of the infant’s tongue, the visible edges indicated that the coating at the center tongue body was much thicker than the tongue borders (where in an adult tongue it would be more clearly thicker just in the center region).  The center of the tongue corresponds to the spleen according to the topography, and the thick white coating indicates deficiency of spleen. With the gathered information, the TCM diagnosis of spleen deficiency resulted in retention of dampness was thus made.