Claimant Hadden herein petitioned the Industrial Accident Board to modify a previously entered compensation agreement on the ground of changed conditions. The Board awarded additional compensation, and the employer and its surety appealed from that order of the Industrial Accident Board.
Claimant Hadden had been employed as a seasonal worker by appellant A & P Tea Company. During the month of January, 1970, in the course of her employment claimant bumped her left elbow, from which she suffered some pain and swelling. During March of the same year she bumped her right elbow and thereafter experienced similar symptoms.
All requirements of notice to the employer were met and thereafter claimant was examined over a number of months by numerous doctors. These examinations culminated in a panel examination by six additional doctors. None of the doctors who examined claimant during these months were able to determine any objective basis for her complaints. Those doctors included, among others, specialists in the fields of internal medicine, psychiatry, neurology and orthopedic surgery. Their tentative diagnoses varied from mild traumatic neurosis and mild traumatic neuritis or bursitis to anxiety reaction or psychosomatic problems. Since claimant had been seen by numerous physicians without any objective findings on their part, the chairman of the examining panel summarized the findings as being essentially negative and suggested that the case be settled with a rating of 5% of loss of one arm at the shoulder.
Claimant and defendants thereafter entered into an agreement which was approved by the Industrial Accident Board. That agreement provided for payment to the claimant for the suggested partial permanent disability and, for a short period, *863of total temporary disability. The amounts stated therein were paid to the claimant and the defendants paid all medical expenses to that date. Thereafter, during November, 1970, claimant was examined at the University of Utah medical center and was diagnosed as suffering from a disease known as dermatomyositis. In March of 1971 claimant filed a petition to modify the compensation agreement on the ground that her condition had changed resulting in an increase of her disability. She asserted that she was then permanently and totally disabled from performing any work. A hearing upon that petition was held before the Industrial Accident Board. The Board thereafter modified the compensation agreement previously entered into by the parties and awarded claimant additional compensation on the basis that she was totally and permanently disabled for any work.
The defendants have appealed from that order of the Industrial Accident Board and their principal assignment of error suggests that the Board failed to require the claimant to prove that her condition had changed and that there was a causal relationship between the industrial accident and the alleged change in condition. Defendants further assert that the record is devoid of any evidence sustaining claimant’s burden of proof and that the evidence is in fact to the contrary, particularly as to the necessary existence of the causal relation between the industrial accident and the change of condition. Defendants point to the Board’s “ultimate findings of fact and conclusions of law” which in part stated: “This agreement and award [previously entered into between claimant and defendant] compensating for any and all complaints is res judicata as to all issues which were raised or could have been raised by defendants as defenses to claimant’s claim for compensation resulting from said accident injury.” Defendants point out that the Board’s conclusion regarding res judicata effectively relieved claimant from the necessity of showing a causal relationship between claimant’s changed condition and the original industrial accident and was error.
Claimant, on the other hand, argues that Blackburn v. Olson, 69 Idaho 428, 207 P.2d 1160 (1949), requires the Board’s res judicata ruling in the case at bar be upheld. Blackburn, and numerous earlier cases cited therein, indicate that the doctrine of res judicata applies to all questions which might have been raised as well to all questions which were raised in the original agreement and award. In Blackburn, however, the Board and the court were dealing with a claimant who had entered into an agreement and thereafter applied for modification on the ground of change in condition. At that point the employer attempted to interject a defense that at the time of the original accident the claimant was engaged in agricultural pursuit which was not covered employment. The Board and court in Blackburn correctly held that the original award and agreement were res judicata as to the question of whether or not the employment was covered.
Such is not the case herein, and we find no authority to uphold the position of the claimant and the Board that the previous agreement and award should be considered res judicata on the question of whether or not there was and is a causal relationship between the original industrial accident and claimant’s alleged change of condition.
We deem the law of Idaho to be clear that “the burden is on the party claiming 'a change of condition’ to prove the change, and that such change was due to and resulted from the prior compensable accident.” Howard v. Washington Water Power Co., 65 Idaho 339, 342, 144 P.2d 210, 211 (1943). See also: Fackenthall v. Eggers Pole & Supply Company, 62 Idaho 46, 108 P.2d 300 (1940); Mell v. Larson, 54 Idaho 754, 36 P.2d 250 (1934).
We note that the court in Mell v. Larson, supra, stated:
“Hearings on the question of a change in condition is authorized under section 43-1407, I.C.A., for the purpose of allowing the board to make an award end*864ing, diminishing, or increasing compensation previously agreed upon or awarded. Such an award under that section of the statute is made entirely on a change in conditions occurring after the date of the previous award, and which change in condition, if for the worse, is directly related to the injury resulting from the accident upon which the first award was based. The hoard and the courts then are restricted to a consideration only of a condition arising after the former award.” (Emphasis added) 54 Idaho 754, 763, 36 P.2d 250, 253.
See also: Craig v. De Berge, 67 Ariz. 168, 193 P.2d 442 (1948); Tinsley v. Goldenstern and Stolpher, 353 P.2d 6 (Okl.1960).
It is sufficient to state that the evidence in this case by a medical expert, appearing by deposition on behalf of claimant, was that whether or not the trauma of the industrial accident produced the then present condition of the claimant could not be resolved. It appears that the cause of the disease is unknown, and if injury should precede the disease it could be purely coincidental. The doctor stated that the particular disease of dermatomyositis is a disease of unknown etiology and that there is no medical literature stating muscle injury or trauma is related to the disease. He stated specifically that anything he might say regarding any relationship between the disease and trauma would be strictly speculative.
Thus it is clear that claimant did not sustain the burden of proof that her changed condition had a causal relationship to the original industrial accident. This court has repeatedly, and most recently in Johnson v. Boise Cascade Corporation, 93 Idaho 107, 456 P.2d 751 (1969), held that findings as to the cause, extent and origin of a disability must be supported by at least some professional proof. In the case of Moeller v. Volco Builders’ Supply, Inc., 81 Idaho 349, 341 P.2d 447 (1959), conflicting medical testimony was offered be:fore the Industrial Accident Board as to the causative agent of ascending myelitis, which had resulted in the death of claimant’s deceased husband. The court therein said:
“Throughout all the expert testimony many inquiries and expressions are directed to the possibility or probability of a bacterial type of infection such as erysipelas becoming the causative agent of ascending myelitis which, in the opinion of some text writers and experts offered in evidence, is due to a virus.
“The issue between the parties involves the causal relationship, if any, of decedent’s skin malady and his back injury to the cause of his death. The answer must be found through evidence submitted by medical experts. From the evidence submitted in this matter, it is convincing that the cause of ascending myelitis has not been determined to a medical certainty. Obviously there is, even to the medical profession, a bewildering array of possible causes, but the causative agent or agents have not as yet been definitely determined.” 81 Idaho 349, 354, 341 P.2d 447, 450.
Having determined that claimant did not sustain her burden of proving a causal relationship between her changed condition and the original industrial accident, there was no evidence before the Industrial Accident Board upon which to base a modification of the original compensation agreement and award. Further, there was no evidence to support the Board’s finding that the claimant was afflicted with the disease at the time she entered into the compensation agreement. The order of the Industrial Accident Board modifying the original compensation agreement and award, being without support therefor, must be and is reversed. The matter is remanded to the Board with instructions to enter its order denying claimant’s petition for modification.
Costs to appellant.
McQUADE, C. J., and DONALDSON, J., concur.