These symptoms may be described in infantile beriberi:

Hoarseness, where the child makes moves to moan, but emits no sound or just faint moans caused by nerve paralysis
Weight loss, becoming thinner and then marasmic as the disease progresses
Vomiting
Diarrhea
Pale skin
Edema
Ill temper
Alterations of the cardiovascular system, especially tachycardia (rapid heart rate)
Convulsions occasionally observed in the terminal stages

Cause
Beriberi is often caused by eating a diet with a very high proportion of calorie rich polished rice (common in Asia) or cassava root (common in sub-Saharan Africa), without much if any thiamine containing animals or vegetables.It may also be caused by shortcomings other than inadequate intake - diseases or operations on the digestive tract, alcoholism, dialysis or genetic deficiencies. All those causes mainly affect the central nervous system, and provoke the development of  Wernickes encephalopathy. Wernickes disease is one of the most prevalent neurological or neuropsychiatric diseases. In autopsy series, features of Wernicke lesions are observed in approximately 2% of general cases. Medical record research shows that about 85% had not been diagnosed, although only 19% would be asymptomatic. In children, only 58% were diagnosed. In alcohol abusers, autopsy series showed neurological damages at rates of 12.5% or more. Mortality caused by Wernickes disease reaches 17% of diseases, which means 3.4/1000 or about 25 million contemporaries. The number of people with Wernickes disease may be even higher, considering that early stages may have dysfunctions prior to the production of observable lesions at necropsy. In addition, uncounted numbers of people can experience fetal damage and subsequent diseases.
Before beginning treatment, prisoners exhibited symptoms of dry or wet beriberi with neurological signs (tingling: 41%), cardiovascular signs (dyspnoea: 42%, thoracic pain: 35%), and edemas of the lower limbs (51%). With treatment, the rate of healing was about 97%.Populations under extreme stress may be at higher risk for beriberi. Displaced populations, such as refugees from war, are susceptible to micronutritional deficiency, including beriberi. The severe nutritional deprivation caused by famine also can cause beriberis, although symptoms may be overlooked in clinical assessment or masked by other famine-related problems. An extreme weight-loss diet can, rarely, induce a famine-like state and the accompanying beriberi. History
Earliest written descriptions of thiamine deficiency are from ancient China in the context of Chinese medicine. One of the earliest is by Ge Hong in his book Zhou hou bei ji fang (Emergency Formulas to Keep up Your Sleeve) written sometime during the third century. Hong called the illness by the name jiao qi, which can be interpreted as "foot qi". He described the symptoms to include swelling, weakness, and numbness of the feet. He also acknowledged that the illness could be deadly, and claimed that it could be cured by eating certain foods, such as fermented soybeans in wine.