Not knowing your age and not having information about your general health, makes it a bit difficult to answer this question but the information you have provided, shortness of
breathBreath alcohol test
Breath holding spell
Breath odor and the skin itching, suggests an allergic component to your problem (despite the negative allergy tests. The most common association of shortness of breath, combined with symptoms of allergy, would occur with asthma. With asthma, the chest X-ray is almost always normal/negative and, in the presence of shortness of breath there is usually, but again not always, wheezing heard by the physician and/or the patient. The itching, in the absence of a rash, is unusual with specific skin diseases but can be seen with dry skin and secondary to drug allergy.
More often, itching without skin lesions occurs with what we call Systemic Diseases. Examples of the latter are kidney failure, endocrine disorders (such as diabetes and thyroid disease), liver diseases and psychiatric disorders. You and your doctor might want to focus on such diseases.
At the same time, attention should be paid to causes of shortness of breath with chest pressure; for example heart disease, lung disease (see above), and emotional causes such as anxiety, with or without what is called Panic Disorder. Attention should first be directed, by your doctor, to physical causes, first and foremost, to the shortness of breath and chest pressure.
Incidentally, relief of your skin symptoms, with antihistamine and steroid therapy, would suggest but not confirm with certainty, an allergic basis for the symptoms.
Good luck